Simplify the specification of expected outputs in some tests, without
changing the meaning, for maintainability and to prepare for a change to the
UnorderedOutput class.

These particular cases are cases where the set of expected lines was lacking
some duplicate lines, which the UnorderedOutput class currently doesn't care
about, and I'm preparing to make it care.

* subversion/tests/cmdline/depth_tests.py
  (diff_in_depthy_wc): Break the diff into named subsets instead of slicing
    a long array with magic numbers. Use diff-formatting helper functions.
    This gives us (correctly) two copies of 'No newline at end of property'
    in the expected output.

* subversion/tests/cmdline/diff_tests.py
  (diff_property_changes_to_base, diff_with_depth): The same. (Some of the
    magic numbers were wrong, but in ways that only meant we were missing
    some duplicate lines in the expected output, which didn't matter.)
    Refactor the code a bit more.

* subversion/tests/cmdline/prop_tests.py
  (propget_redirection): Calculate the expected huge property value instead
    of repeating its definition with only a tiny mechanical change. Explain
    why the expected value is not exactly the same as the value we set.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1444198 13f79535-47bb-0310-9956-ffa450edef68