Make it possible to call setup.py install -user for installation to user directory on Linux
imagemanip: small corrections
added new ContextMenu class with a simple interface for managing right click menu items
mainframe: remove old selection_menu stuff
Add plugin hooks for image browser context menu
bin/picty lost its execute bit
imagewriter: correctly write files with non-jpg extensions
imagewriter: previous commit was incorrect, should be using the destination file extension
user guide: started on collections explanation, tweaks to to user_interface
Don't try to override default styles until the gui has been created and enclose those overrides in try/except block to prevent crash on some systems. Fixes issue #3.