In tests for failing hook scripts, include non-XML-safe characters in the hook failure messages in order to regression-test issue #3553 ("mod_dav_svn not XML-escaping hook error messages"). Also simplify the test code a little.
In tests for failing hook scripts, include non-XML-safe characters in the
hook failure messages in order to regression-test issue #3553 ("mod_dav_svn
not XML-escaping hook error messages"). Also simplify the test code a little.

* subversion/tests/cmdline/commit_tests.py
  (post_commit_hook_test, start_commit_hook_test, pre_commit_hook_test):
    Include non-XML-safe characters in the hook failure message.  In the
    latter two tests, simplify the code by using the existing function
    create_failing_hook() to create the hooks.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@893536 13f79535-47bb-0310-9956-ffa450edef68

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