Add some testcases for svn_path* functions.
Add some testcases for svn_path* functions.

Note that one of the testcases shows that our use of svn_path functions on both
urls and dir entries is neither well documented nor correct. Solving issue 
#1711 should fix this.

* subversion/tests/libsvn_subr/path-test.c
  (test_path_is_ancestor): Add some new testcases.
  (test_get_longest_ancestor): ... And here too.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@870555 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion