Update Xwayland path in mutter. It changed, and I forgot to change it

Remove --with-xwayland-path from build scripts that don't need it

git-svn-id: https://rebeccablackos.svn.sourceforge.net/svnroot/rebeccablackos@2544 56e3d1a8-0179-4092-b3e2-9fbbcda0c0a9