[Bf-codereview] Convex hull unit tests (issue 6737066)

[NicholasBishop at gmail.com]

Reviewers: bf-codereview_blender.org,

Description:
This is an experiment with writing some simple unit tests. I'm working
on some changes to the convex hull tool, so I wrote a few test cases for
that. In general I think it'd be nice to have a place to put tests
written in C (we already have some Python tests, but some things are
easier to test in C, particularly where the Py API is missing stuff.)


Commit message
==============

Add C unit tests for convex hull

* Add a new "--unit-tests" command line option for Blender. It is only
available when compiling in debug mode.

* Add a small set of unit tests for convex hull. They are definitely not
providing complete coverage yet.

TODO:

* Add unit tests for other tools.

* Consider using an existing unit-testing library for more advanced
features.

Please review this at https://codereview.appspot.com/6737066/

Affected files:
   build_files/scons/tools/Blender.py
   source/SConscript
   source/blenderplayer/bad_level_call_stubs/stubs.c
   source/creator/CMakeLists.txt
   source/creator/creator.c
   source/tests/CMakeLists.txt
   source/tests/SConscript
   source/tests/unit_test.c
   source/tests/unit_test.h
   source/tests/unit_test_convex_hull.c
   source/tests/unit_test_intern.h