Recursively copy library dependencies into destination package. Identify libraries...

Recursively copy library dependencies into destination package.  Identify libraries to be installed based on the path in which they are located, rather than whether there is "libSDL" in the name.  Use install_name_tool to change the search path so that the system looks for libraries in @executable_path@ rather than their location on the machine upon which the program was built.

git-svn-id: https://chocolate-doom.svn.sourceforge.net/svnroot/chocolate-doom/trunk/chocolate-doom@1796 ee5ca603-980d-0410-972c-a23fc50d79fe