* src/Makefile.am : Added TreeTip.py to list of installed modules.
* src/TreeTip.py: New module that implements tooltips on TreeView rows.
* src/plugins/Makefile.am: Added ScratchPad.py and scratchpad.glade.
* src/plugins/ScratchPad.py: New module to implement a scratch pad for
temporary storage of drag and drop objects.
* src/plugins/scratchpad.glade: New glade file for ScratchPad window.
svn: r4184
