Unfortunately this doesn't make all tests compilable due
to all sort of weird and wonderful bad levels includes
on Windows (G referenced from bf_blenlib) but at least
allows to selectively build tests for now.
The idea is to split them into two separate targets and have dedicated include
directories list for each of them in order to avoid some annoying include header
modifications in comparison with upstream.
Reviewers: campbellbarton, juicyfruit
Differential Revision: https://developer.blender.org/D1706
Generally for build systems, libraries that do not depend on other
libraries, such as system libraries, OpenGL etc always go at the end.
We could even get rid of some duplicate dependency libraries here but
auto duplication by build systems and differences between OSs make this
difficult.
GTest still duplicates all libraries twice to solve some issues which is
weird (maybe libs are not sorted correctly for some reason? needs
investigation)
