Blender Git Loki

Build: add config for developers

This has faster builds, error checks and tests. The number of cmake options
for this type of thing has grown over the years and it's convenient to be
able to point new developers to a single target.

Previously the combination of all these options did not work correctly, now
all tests should pass.

The easiest way to use this is with the make wrapper, for example:
make full developer debug

Or set it manually with CMake:
cmake -C ../blender/build_files/cmake/config/blender_developer.cmake .

Differential Revision: https://developer.blender.org/D5149