added text field for selected description, added list of selected objects
polyline is selected after creation, deselection seems to work
added full polyline selection/deselection
added polytope selection/deselection
hooked up selection signal
added some notes on picking
split out selection between ortho and perspective, added abstract
sceneobj/ray intersection class
added ray/sphere intersection, first pass at polyline selection working
added virtual destructor to sceneobject interface to fix destruction
problem, added deletion for selected objects
fixed crash at exit
added point set intersection method
added pointset destructor
added picking to perspective... doesn't work exactly as expected - need to
construct different direction vector, currently just uses camera direction
irrespective of click
hooking up selected obj to context menus
Merge pull request #6 from freemancw/selection-fixes

Selection fixes