Merge r1210221:

Change the provider names to match the module names:
mod_slotmem_shm: shared -> shm
mod_socache_memcache: mc -> memcache


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1210224 13f79535-47bb-0310-9956-ffa450edef68