add cmake module that finds libSquish via "find_package(libSquish)" in cmake projects


git-svn-id: http://libsquish.googlecode.com/svn/trunk@45 995b7d7e-cf50-0410-b6c9-9f4ebe303554
tweak cmake message

git-svn-id: http://libsquish.googlecode.com/svn/trunk@46 995b7d7e-cf50-0410-b6c9-9f4ebe303554