in the path anymore (e.g. certain suse versions), which means the
desktop files didn't work. Now the configured path is automatically
inserted into the desktop file.
Additional the categories was shortened.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/trunk/supertuxkart@1914 178a84e3-b1eb-0310-8ba1-8eac791a3b58