jsPlumb 官方示例，支持IE6

* 1.6.2 BACKWARDS COMPATIBILITY - 1.6.2 has improved behaviour for determining what element to use as the Container. Previous 1.6.x versions defaulted to the document body, with the docs strongly recommending you set a Container. From 1.6.2, if there is no Container set when the user makes a first call to either addEndpoint, makeSource, makeTarget or connect, the Container is set to be the offsetParent of either the element being configure (in the case of `addEndpoint`, `makeSource` and `makeTarget`), or the source element, for the `connect` method. - a consequence of this is that you can no longer manipulate Defaults.Container manually. Your changes will be ignored; Defaults.Container is only referenced in the constructor or in the `importDefaults` method. If you need access to the current Container, use the `getContainer` method. - the order of parameters to the function `jsPlumbInstance.on` has changed, in the case that you are passing 4 parameters and using it for event delegation. Previously, the order was `(element, filter, eventId, callback)` and now the order is `(element, eventId, filter, callback)`. This brings it into line with the order of parameters in jQuery's `on` function. It is not very likely this will affect you; `jsPlumbInstance.on` is used internally, mostly (although it can be used to register events independently of jsPlumb if you want to use it). NEW FUNCTIONALITY - The Container inferencing discussed above is both a backwards compatibility issue and also new functionality! - added setContainer, to allow you to move an entire jsPlumb UI to some new parent - added getContainer, to allow you to retrieve the current Container. ISSUES 207 - problem with absolute overlays 211 - setVisible(true) on hidden overlay whose connection has moved causes the overlay to repaint in the wrong place * 1.6.1 BACKWARDS COMPATIBILITY No issues NEW FUNCTIONALITY - Better handling of zooming in vanilla jsPlumb. ISSUES 206 Fix documentation error about jsPlumb.Defaults.Endpoints * 1.6.0 BACKWARDS COMPATIBILITY - Connection's `mouseexit` event was renamed to `mouseleave`. - There is no support for the canvas renderer in jsPlumb 1.6.0. - The way in which library adapters inject their functionality into jsPlumb has changed. This will affect very few people; contact jsPlumb if you need help with this. - All elements added by jsPlumb are appended to the current "Container", which defaults to the document body. This differs from previous versions, in which if there was no Container set then jsPlumb would append elements to the parent of a connection's source endpoint. For this reason it is now more than ever recommended that you set a Container. - The `container` parameter on `addEndpoint` or `connect` calls is no longer supported. NEW FUNCTIONALITY - introduced a version of jsPlumb ("Vanilla") that does not depend on jQuery, YUI or MooTools. - added support (in Vanilla jsPlumb) for multiple element dragging - added support (in Vanilla jsPlumb) for multiple drag/drop scopes - add setSource/setTarget methods, allowing you to retarget a Connection programmatically. ISSUES 91 - Old ID is being used on events after setId 143 - SVG gradient fails when page url already contains a hash 153 - jsPlumb.animate no longer supports jQuery selectors 157 - connectionMoved event not fired (when using makeTarget) 162 - Connector 'Flowchart' occurs an error. 164 - makeSource fails when used in conjunction with uniqueEndpoint 173 - jsPlumb.setDraggable([element_id],false); fails 177 - Flowchart straight Line 202 - spurious mouse events in connector with outline 203 - hoverClass on endpoints doesn't work MISCELLANEOUS - events now have "this" set correctly - added qunit tests and load tests for Vanilla, YUI and Mootools versions - various YUI and Mootools methods were upgraded to support passing in an element list (setId for one) - reduced the amount of functionality that is delegated to a support library - rewrote the way support libraries are integrated * 1.5.5 ISSUES 138 - allow for connection type to be derived from connection params AND endpoint params. * 1.5.4 ISSUES 105 - Blank endpoint cleanup fails 116 - Assign anchors wont connect 117 - Assign anchors fail on source 127 - Docs on making elements draggable should note required CSS 128 - expose original event on connectionDragStop callback 129 - connection event fired twice by makeTarget with parent option. NEW FUNCTIONALITY - "Assign" anchors now work with the makeSource method. MISCELLANEOUS - fixed an issue causing SVG gradients to fail when a BASE tag is present in the document. * 1.5.3 BACKWARDS COMPATIBILITY - The fix for issue 112 involved making a change to the circumstances under which a `connectionDetached` event is fired. When you drag the source or target of an existing connection to some other endpoint, `connectionDetached` is no longer fired. Instead, a `connectionMoved` event is fired, containing the connection that was moved, the index of the endpoint that changed (0 for source, 1 for target), and the original and new source and target endpoints. ISSUES 77 - Endpoint types should support Anchor parameter 88 - reinstate labelStyle parameter on Label overlay. 90 - overlay setVisible not working (SVG/VML) 95 - Nested element positions not updated 100 - add setParent function 101 - JS error when detaching connection during connection callback 103 - IE8: connector hide does not hide overlays or background lines 108 - strange anchor orientation behaviour 107 - remove the necessity to set isSource/isTarget in order to make an endpoint draggable 109 - Dropping new connections on overlapping elements leads to crash after connection is deleted 111 - Absolute positioned arrow in wrong location 112 - Deleting a connection after changing its source endpoint causes failure. 113 - IE8 - state machine - loops are not displayed NEW FUNCTIONALITY - a setParent function was added. jsPlumb changes the parent of some element and updates its internal references accordingly (issue 100). - Endpoint types now support the anchor parameter (issue 77) - The labelStyle parameter on Label overlays has made a comeback (issue 88). The argument went along the lines of it being useful if you wanted to programmatically generate a label style. - jsPlumb now automatically updates the internal offsets of some element that has draggable children (obviating the need for you to call `recalculateOffsets` yourself). - when making a programmatic connection to an endpoint that was not marked isSource:true or isTarget:true, if the connection is detachable then the endpoint is made draggable, in order to allow users to drag the connection to detach it. Connections dragged off of source or target endpoints in this way can be dropped back onto their original endpoint or onto other endpoints with the same scope, but you cannot subsequently drag a new connection from an endpoint that has been made draggable by this method. MISCELLANEOUS - an issue was fixed that was preventing the ability to supply a dynamic anchor with parameters, eg [ [ [ 1,0,0,1], [1,1,1,1] ], { selector:function() { ... } } ] * 1.5.2 BACKWARDS COMPATIBILITY - Issue 86, fixed in 1.5.2, changes the priority in which parameters are applied to a connection. The documentation has always stated that source takes priority, but in fact the code was the other way round, with target taking priority. Now source does take priority. ISSUES 84 - jsPlumb 1.5.1 Arrow Disappears on IE8 when connector is straight 85 - dragging target endpoints created by makeTarget not working 86 - Connection "parameters" override order MISCELLANEOUS - An issue that caused the SVG renderer to paint overlays before the connector was read