Separate the setup of the deeptree tests from the actions file in the test
suite. This cleans up the code and avoids loading 1000 lines of python on
almost every test invocation when running tests parallel.

* subversion/tests/cmdline/merge_tree_conflict_tests.py
  (imports): Add deeptrees.
  (*): s/svntest.actions.deep/svntest.deeptrees.deep/
       s/svntest.actions.Deep/svntest.deeptrees.Deep/

* subversion/tests/cmdline/svntest/actions.py
  Remove all deeptrees code. Copy Item abbreviation as that is being used
  in the actions code.

* subversion/tests/cmdline/svntest/deeptrees.py
  Copied from actions.py. Remove actions.py code, but import everything from
  actions.

* subversion/tests/cmdline/switch_tests.py
  (*): s/svntest.actions.deep/svntest.deeptrees.deep/
       s/svntest.actions.Deep/svntest.deeptrees.Deep/

* subversion/tests/cmdline/update_tests.py
  (*): s/svntest.actions.deep/svntest.deeptrees.deep/
       s/svntest.actions.Deep/svntest.deeptrees.Deep/


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1443282 13f79535-47bb-0310-9956-ffa450edef68