Move GLES20 source into standard locations
Move Khronos headers into their respective components, to be exported by each.
Remove hostthreadadapter as nothing outside of the vghwapiwrapper, which now contains the code, needs it
#ifndef _IDISPIDS_H
#define _IDISPIDS_H
#if __GNUC__ >=3
#pragma GCC system_header
#endif
#define DISPID_AMBIENT_OFFLINEIFNOTCONNECTED (-5501)
#define DISPID_AMBIENT_SILENT (-5502)
#endif