Implement GHCI hot code reloading. Still segfaults sometimes
Beautify State initialization
Add transient state to contain things that can't survive reloads.

Fixes segfault when restart is called with existing point clouds.
Initialize OpenNI only once (speeds up taking snapshots)
Make (width,height) a tuple
Use spool
fixup! Initialize OpenNI only once (speeds up taking snapshots)
Fix some warnings
Represent point clouds as Vector Vec3 (use vect)
Remote initial green points
Add drawing correspondence lines
Honi: Don't ignore initialize return value
Remove bad flush
Use double buffering
Experiment with stencil picking
Implement color picking
Small cleanup
Add loading/drawing point clouds and pickable polygons