windows compilation with multiple files

- and activate warnings
timed_compile properly returns the return code from compile
vstudio does not support fixed sized array arguments references
OpenGL import for windows
factorize vstudio from windows8 entry point

this makes it easy to add a new vstudio config
basic null runtime for windows
pass and accept linker flags
Merge branch 'F-NullRuntimeOnWindows'

Windows compiles (tested windows 8 with vstudio express) with a null
(inoperative) runtime.

* F-NullRuntimeOnWindows:
  pass and accept linker flags
  basic null runtime for windows
  factorize vstudio from windows8 entry point
  OpenGL import for windows
  vstudio does not support fixed sized array arguments references
  timed_compile properly returns the return code from compile
  windows compilation with multiple files