Item11267: More submodule changes

 - Install githooks even if no MANIFEST exists.
 - Handle multiple cases:  Simple repo,  submodule repo
 - Also make sure core submodule gets hooks, as it is not directly
   pseudo-installed

git-svn-id: http://svn.foswiki.org/trunk/core@17841 0b4bb1d4-4e5a-0410-9cc4-b2b747904278