configure.in:
  Fix directories built using --without-server, and add mf_keycache.o
  to list of objects only built for thread-safe library, since it requires
  threading.
dbug/my_main.c:
  Don't try to initialize thread globals if not built with threading.
mysys/Makefile.am:
  Remove mf_keycache.c from list of files to build (it will be included
  in THREAD_LOBJECTS when appropriate).
mysys/mf_getdate.c:
  Fix usage of gmtime().
sql/share/Makefile.am:
  Allow removal of mysqld_error.h to fail, in case it doesn't exist yet.
tests/Makefile.am:
  Don't link against libmysys explicitly.