* cygheap.h (class cygheap_user): Use INVALID_HANDLE_VALUE as invalid

	* cygheap.h (class cygheap_user): Use INVALID_HANDLE_VALUE as invalid
	value for tokens.
	* syscalls.cc (seteuid32): Ditto.  Set new_token to process token if
	process token is suitable.
	* uinfo.cc (uinfo_init): Initialize tokens in cygheap user info
	to INVALID_HANDLE_VALUE.

	* cygheap.h (enum impersonation): Delete.
	(cygheap_user::impersonation_state): Delete.
	(cygheap_user::current_token): New.
	(cygheap_user::issetuid): Modify to use current_token.
	(cygheap_user::token): Ditto.
	(cygheap_user::deimpersonate): Ditto.
	(cygheap_user::reimpersonate): Ditto.
	(cygheap_user::has_impersonation_tokens): Ditto.
	(cygheap_user::close_impersonation_tokens): Ditto.
	* security.cc (cygwin_set_impersonation_token): Always set the token.
	(verify_token): Change type of gsid to cygpsid.
	(get_file_attribute): Use the effective ids.
	* syscalls.cc (seteuid32): Modify to use cygheap_user::current_token.
	* uinfo.cc (uinfo_init) Do not set cygheap->user.impersonation_state.