* cygheap.h (cygheap_user): Reorg to accommodate environment caching.

* cygheap.h (cygheap_user): Reorg to accommodate environment caching.
(cygheap_user::logsrv): New method.
(cygheap_user::winname): Ditto.
(cygheap_user::domain): Ditto.
(cygheap_user::test_uid): Ditto.
* cygheap.cc (cygheap_user::set_name): Reflect name "pwinname" name change.
* environ.cc (getwinenveq): New function.
(spenv::from_cygheap): Change arguments.
(spenv::retrieve): Ditto for call.  Use getwinenveq to retrieve info from
environment.  Always return value from cygwin environment, if it exists.
* environ.h (getwinenveq): Declare.
* uinfo.cc (cygheap_user::ontherange): Use logsrv() rather than env_logsrv().
(cygheap_user::test_uid): Define new method.
(cygheap_user::env_logsrv): Accept environment arguments.  Use test_uid to find
info.
(cygheap_user::env_domain): Ditto.
(cygheap_user::env_userprofile): Ditto.
(cygheap_user::env_homepath): Ditto.
(cygheap_user::env_homedrive): Ditto.
(cygheap_user::env_name): Ditto.