When the Moon is full it was possible to have a dead-lock in task
scheduler's exit() method.
Similar problem was fixed in Blender's task scheduler 3 years ago
in bae2a2c.
This is an initial move to have unittests to at least cover
utility functions, which then could be extended further to
test such areas as shader optimization and such.
Currently only based on initial "infrastructure" layout and
writing tests needed to test the no-boost patch.
Note: This patch starts to use "<dir>/<header>.h" notation
for the include statements which i just got used to do in
other projects. Something what would be cool to use globally
in the code eventually.
Reviewers: dingto, juicyfruit, lukasstockner97, brecht
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D1770