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 _RPCNTERR_H
#define _RPCNTERR_H
#if __GNUC__ >=3
#pragma GCC system_header
#endif
#define RPC_S_OK ERROR_SUCCESS
#define RPC_S_INVALID_ARG ERROR_INVALID_PARAMETER
#define RPC_S_OUT_OF_MEMORY ERROR_OUTOFMEMORY
#define RPC_S_OUT_OF_THREADS ERROR_MAX_THRDS_REACHED
#define RPC_S_INVALID_LEVEL ERROR_INVALID_PARAMETER
#define RPC_S_BUFFER_TOO_SMALL ERROR_INSUFFICIENT_BUFFER
#define RPC_S_INVALID_SECURITY_DESC ERROR_INVALID_SECURITY_DESCR
#define RPC_S_ACCESS_DENIED ERROR_ACCESS_DENIED
#define RPC_S_SERVER_OUT_OF_MEMORY ERROR_NOT_ENOUGH_SERVER_MEMORY
#define RPC_X_NO_MEMORY RPC_S_OUT_OF_MEMORY
#define RPC_X_INVALID_BOUND RPC_S_INVALID_BOUND
#define RPC_X_INVALID_TAG RPC_S_INVALID_TAG
#define RPC_X_ENUM_VALUE_TOO_LARGE RPC_X_ENUM_VALUE_OUT_OF_RANGE
#define RPC_X_SS_CONTEXT_MISMATCH ERROR_INVALID_HANDLE
#define RPC_X_INVALID_BUFFER ERROR_INVALID_USER_BUFFER
#define RPC_X_INVALID_PIPE_OPERATION RPC_X_WRONG_PIPE_ORDER
#endif