Add a regression test for "svn blame" on lines of unknown revision.
Add a regression test for "svn blame" on lines of unknown revision.

Patch by: Alexander Thomas <alexander@collab.net>
	  me

* subversion/tests/clients/cmdline/blame_tests.py
  (blame_on_unknown_revision): New test.
  (test_list): Add the test.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion