Generate verstub.cpp through raw cmake.

There is no need for an extra program.

As a bonus, generate a consistent windows vdi file.

There is still an issue with actually *reading* the vdi, but that's for someone else to tackle.

src/StepMania.cpp

@@ -919,13 +919,12 @@ static void MountTreeOfZips( const RString &dir )
 	}
 }
 
-
 static void WriteLogHeader()
 {
 	LOG->Info("%s%s", PRODUCT_FAMILY, product_version);
 
 #if defined(HAVE_VERSION_INFO)
-	LOG->Info( "Compiled %s @ %s (build %lu)", version_date, version_time, version_num );
+	LOG->Info( "Compiled %s @ %s (build %s)", version_date, version_time, ::sm_version_git_hash);
 #endif
 
 	time_t cur_time;