Allow ZLIB_LIBDIR to be set to specify where the output of the zlib build can be found.
Allow ZLIB_LIBDIR to be set to specify where the output of the zlib build
can be found.

* serf.mak: Support zlib with MSVC 2005 builds.


git-svn-id: 683495cb1553624b05a54e2ba9533425f69cf277@1069 61a7d7f5-40b7-0310-9c16-bb0ea8cb1845

coapp-packages/serf,coapp-packages/serf,coapp-packages/serf