1) Add --with-distcache to configure for choosing

the distcache installation directory.

2) Use correct build variable MOD_SOCACHE_DC_LDADD
instead of MOD_SOCACHE_LDADD in build macro.

Also made the macro a bit more consistent with the
SSL checking macro.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1142648 13f79535-47bb-0310-9956-ffa450edef68