Added some basic geometric primitives such as planes, rays, segments
and lines (plus some extra functions like xProject, xBarycentric, Lerpf),
as well as some intersection tests between them.
Additionally, I split massive math test into smaller ones and tweaked
unit test library (testing no longer stops after first failure).
After a while I felt that putting underscores between words was not the
best solution, so I changed the underscores to capital letters.
Fixed consistency bug between POSIX/Win32 platform in BH_FileOpen.
Removed definitions for math types (vector, matrix, etc.) due to
potential aliasing issues.
Added Asan profile to help catch and fix various bugs (and indeed, there
were few of them).
Additionally, fixed bhunit macro to process arguments only once.
After some testing, I decided to ditch the DirectX approach of writing
math functions.
Additionally, I added unit tests (with reference wxMaxima calculations)
for most math functions and fixed several bugs along the way.
