To support unloading dynamic modules, add a new element to the module

structure: dynamic_load_handle. This contains the handle of the
dynamically loaded module (used by mod_dll and mod_so) so it can be
unloaded later. This is initially set to NULL by the STANDARD_MODULE_STUFF
so no changes are needed to modules. Any shared modules built up to
now should be rebuild (the MMN could be bumped, but I don't think many
people will have big libraries of pre-built .so's yet. Oh, they might
have DLL's though. Um, prehaps MMN should be bumped up).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80140 13f79535-47bb-0310-9956-ffa450edef68