build script: move object files to subdir

also:
- protect usage of src files array
- choose architecture for vstudio compilations
- share common flags between windows7 and 8 in compile_NT
add static-analysis build with clang
load OpenGL using GLEW

just import GL/glew.h to get access to all the OpenGL functions.

also made it possible to call the build script from anywhere
Merge branch 'F-include-gl-loader'

* F-include-gl-loader:
  load OpenGL using GLEW
  add static-analysis build with clang
  build script: move object files to subdir