Proof of concept: automatically import C header files

[Jacob Carlborg]

Made a proof of concept to automatically parse, translate and import C 
header files in D using DStep. DMD is linked against DStep and does not 
start new process to make the translation.

I added a new pragma, include, that handles everything. Use like this:
// foo.h
void foo ();

// main.d

module main;

pragma(include, "foo.h");

void main ()
{
    foo();
}

DMD: https://github.com/jacob-carlborg/dmd/tree/dstep
DStep: https://github.com/jacob-carlborg/dstep/tree/c_api

--
/Jacob Carlborg