Adding WINRT platform support to bx.
Merge pull request #17 from dariomanesku/master

Added include for alloca.h on OS X.
Add FreeBSD support to the codebase.

The FreeBSD-specific compatibility changes are invoked when the
__FreeBSD__ macro is defined, which is the default for (I think all?)
toolchains on FreeBSD. This turns on the BX_PLATFORM_FREEBSD macro which
can be used for further specializations.

FreeBSD is a mix between Linux, NaCl and OSX, with some extra cavaets that
have been worked around:

 * malloc.h is deprecated; FreeBSD uses stdlib.h instead.
 * alloca.h doesn't exist; it's also in stdlib.h.
Merge pull request #19 from lye/freebsd-platform-code

Add FreeBSD support to the codebase.
Cleanup.
Added FreeBSD to toolchain.lua.
Cleanup.
Added thread test.
Merge branch 'master' of https://github.com/MikePopoloski/bx
Fixing WinRT issues in newly added platform functions.
Merge pull request #20 from MikePopoloski/master

Adding WinRT platform to bx
Cleanup.
Cleanup.
Cleanup.
Added bx::CommandLine test.
Cleanup.
Added atomicTestAndInc/Dec.
Cleanup.
Fixed VS2012 compile error.
Added baseName to extract base file name from file path.