Hash maps for point and segment buffers + small improvements
Slightly improved ui
Smooth points
Interactive viewer added
Segment intersection visualization
Fixed choose distance (now depends on zoom)
Interactive segment now uses interactive points
Interactive triangle added
Triangle contains point example simplified
Points are now drawn ower lines
Now both keyPress and keyRelease can be handled
Mouse events renamed
Renamed & added methods (get_point, set_point, etc.)
Refactoring
Interactive axis-aligned rectangle
get_point returns reference
Merge branch 'visualization-refactoring' of git://github.com/lisyarus/cg

Conflicts:
	examples/operations/triangle_contains_point.cpp