- On leopard (Mac) machine the X11 libraries live in /usr/X11/lib, but only    libXt*.dylib exist (or libXt.la). Adding "dylib" to the extension set allows    configure to complete without error.
- On leopard (Mac) machine the X11 libraries live in /usr/X11/lib, but only 
  libXt*.dylib exist (or libXt.la). Adding "dylib" to the extension set allows 
  configure to complete without error.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@22268 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,dawehner/root,dawehner/root,dawehner/root,dawehner/root,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,dawehner/root,dawehner/root