make shared moduled and module set "most" the default.

Static building can be achieved with --enable-mods-static
or as previously using --enable-MODULE=static.
The existing --enable-mods-shared still works for
compatibility with existing build scripts.

Modules build with --with-module=... will still be build static.
For dynamic builds of external modules there is apxs.

The default set of modules os now "most". To build a small
set of modules use the new "few".

If APR doesn't support DSOs we fall back to static binding.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@952007 13f79535-47bb-0310-9956-ffa450edef68