Though it still is not possible to create a new window from a thread that did not init SDL

Scene rendering logic is now better

Box objects (AABB) now have the long awaited extent() and center()
methods. Corners are now called “aa” and “bb” for convenience. The
WorldEntity class uses a box3 for its AABB instead of two vec3s.
This allows us to simplify a lot of verbose code.

Reworked Primitive logic for scene rendering
FileUpdateTester works now .....

Revamped thread communication
Fixed dynamic thread Add/Remove
Added unit-test for threads !!!!

- removed 177 CR characters
 - removed 12 trailing whitespaces
 - replaced 0 tabs with spaces
 - fixed 1 svn:eol-style properties

MeshViewer first pass