Remove it except for two things in qerror.h:

* Two #include to be cleaned up separately to avoid cluttering this
  patch.

* The QERR_ macros.  Mark as obsolete.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>