Need a sp_cache_remove() function with implicit name lookup to make the WL task
to work. It's a cleaner and more convenient interface anyway...


sql/sp.cc:
  Modified sp_cache_remove() function calls; just remove by name.
sql/sp_cache.cc:
  Modified sp_cache_remove() function. Get name and lookup/remove, return the
  removed entry, if any.
sql/sp_cache.h:
  Modified sp_cache_remove() function. Get name and lookup/remove, return the
  removed entry, if any.