auto mac / linux / win / 32/64 bit detection
makefile revisions
makefile
159
- platform detection via #ifdef
- renamed os.c to main.c, renamed a few functions
Merge branch 159 into feature/makefile

Conflicts:
	build_c_linux32.sh
	build_d_linux64.sh
	build_e_mac_os32.sh
	build_f_mac_os64.sh
	build_g_win32.bat