Clean up the test suite's display_lines() function a bit.

* subversion/tests/cmdline/svntest/actions.py
  (setup_pristine_greek_repository): Remove the display_lines() call here,
    because it was unexecutable: run_svn() would have done so and raised
    an exception if there was any error.

* subversion/tests/cmdline/svntest/verify.py
  (display_lines_diff): New function, extracted from display_lines().
  (display_lines): Don't pretend to know about different kinds of data, and
    don't display a diff. Just display the data and labels that the caller
    provides.
  (ExpectedOutput, RegexOutput,
   UnorderedOutput, UnorderedRegexOutput,
   verify_exit_code): Adjust callers.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1443474 13f79535-47bb-0310-9956-ffa450edef68