Correct use of libtool: libtool convenience libraries which are to be

Correct use of libtool: libtool convenience libraries which are to be
linked directly into a program must be linked using -static and not
-module.  Fixes build issues with libtool HEAD.

* acinclude.m4 (APACHE_MODPATH_ADD): For a static module, use a
filename with a lib prefix.

* build/rules.mk.in (MOD_LINK): Use -static not -module.

* build/special.mk (install-modules): Adjust special-case for
installation of shared modules to look for libso.la not mod_so.la.

* build/library.mk: Link libraries using -static.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@102381 13f79535-47bb-0310-9956-ffa450edef68