Seamless integration of added OS-header files

All OS files such has `windows.h' and `elf.h' will now be implemented
and stored in libos/.  The C file itself need not know this, as it
continues it `#include <windows.h>', and this will be achieved via
compiler flags.
Magical makefiles for braindead builds
Exclude binaries and GCC junk from VCS
Merge branch 'feature/x-compile' into develop
Merge from master at b50aa01
Merge branch 'develop'
merge and lib fix