introducing SplitPanel and enable 2 editor window on the screen
remove user-select-on clas deinition from panel-header-title
remove obsolete code
DiagramDesigner trigger UI activity on any user action that happend in the editor
initial clipboard support

- clipboard support with fake hidden textarea control (bcos of Firefox)
- add clipboard support for DiagramDesignerWidget (onCopy implemented,
onPaste missing)
- add clipboard support for ModelEditorPanel and ModelEditorControl
bugfix: message to the user if feature not available in browser
MetaEditorPanel supports itnerface ISupportClipboard

!!!! MetaEditorController still has no support for onCopy / onPaste
implement onPaste in ModelEditorControl

intellyPaste the nodes with the carried ID
error message fix
cleanup
don't enable create reference to itself while drag&drop
create reference mouse cursor icon
code cleanup
getSelectedElements fix to return the cloned array not the original
droppable tolarance is set to 'pointer'

http://api.jqueryui.com/droppable/#option-tolerance
"pointer": Mouse pointer overlaps the droppable.
expose start. drag and stop callbacks and createDragInfo receives event parameter
DiagramDesignerWidget item drag&drop is handled with juqeryUI and ghost box dragging insted of live feedback

DiagramDesignerWidgetDraggable
Merge branch 'master' of https://github.com/webgme/webgme
implement SplitPanel resize functionality
constraints have been introduced to core