Finished basic MonoD generator support (compiler/linker settings are not yet emitted).

Dub builds with VisualD with latest vibe. BuildPlatform is passed from app.d to the generators. System libraries are suffixed with '.lib' for VisualD.

Renamed Application to Project and put it into its own module + added a stub MonoD generator.

Initial commit (more or less the same code as used for vibe.d's vpm).