Second part of Issue 103: tracking of mouse events and new 'rotate' state.  Does not actually rotate the element yet.
Second part of Issue 103: tracking of mouse events and new 'rotate' state.  Does not actually rotate the element yet.

git-svn-id: e52e7dec99011c9686d89c3d3c01e7ff0d333eee@477 eee81c28-f429-11dd-99c0-75d572ba1ddd

chunchill/svg-edit,soranchu/svg-edit,luqin/svg-edit,cagataygoncu/svg-edit-gravvitas,soranchu/svg-edit,soranchu/svg-edit,luqin/svg-edit,cagataygoncu/svg-edit-gravvitas,djyaron/svg-edit,luqin/svg-edit,nilclass/svg-edit,svn2github/svg-edit,chunchill/svg-edit,nilclass/svg-edit,djyaron/svg-edit,chunchill/svg-edit,daleharvey/svg-edit,chunchill/svg-edit,dogmatic69/SVG-Edit,dogmatic69/SVG-Edit,svn2github/svg-edit,daleharvey/svg-edit,djyaron/svg-edit,djyaron/svg-edit,daleharvey/svg-edit,luqin/svg-edit,cagataygoncu/svg-edit-gravvitas,dogmatic69/SVG-Edit,nilclass/svg-edit,svn2github/svg-edit