removing swig from the list of automatically built sudirectories, and instead...

removing swig from the list of automatically built sudirectories, and instead adding swig/Makefile to the list of config files generated by autoconf

git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@636715 13f79535-47bb-0310-9956-ffa450edef68