avoid hardcoding X11 lib path, explicitly call included AC_PATH_X
avoid hardcoding X11 lib path, explicitly call included AC_PATH_X

git-svn-id: 620571fa9b4bd0cbce9a0cf901e91ef896adbf27@33716 d073be05-634f-4543-b044-5fe20cf6d1d6

macports/macports-base,danchr/macports-base,neverpanic/macports-base,danchr/macports-base,neverpanic/macports-base,macports/macports-base