Minor simplification of the cache stats code.  Clear the aggregated
stats strcut before passing it on to the specific implementatations.

* subversion/libsvn_subr/cache.c
  (svn_cache__get_info): clear all stats before filling them

* subversion/libsvn_subr/cache-membuffer.c
  (svn_membuffer_cache_get_info): simplify

* subversion/libsvn_subr/cache-memcache.c
  (memcache_get_info): simplify

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1489855 13f79535-47bb-0310-9956-ffa450edef68
Move the merge test helper code that is used outside merge_tests.py to a new
helper file, to remove a dependency on 18500 lines of python in each test.

For now name the file after a similar file for treeconflicts. This code
should eventually be refactored to a more generic form.

* subversion/tests/cmdline/blame_tests.py
* subversion/tests/cmdline/log_tests.py
* subversion/tests/cmdline/mergeinfo_tests.py
* subversion/tests/cmdline/merge_authz_tests.py
* subversion/tests/cmdline/merge_automatic_tests.py
* subversion/tests/cmdline/merge_reintegrate_tests.py
* subversion/tests/cmdline/merge_tree_conflict_tests.py
* subversion/tests/cmdline/resolve_tests.py
  (imports): Import from svntest.mergetrees instead of merge_tests.py

* subversion/tests/cmdline/merge_tests.py
  (imports): Explicitly import everything from svntest.mergetrees.

  (expected_merge_output,
   check_mergeinfo_recursively,
   set_up_dir_replace,
   set_up_branch,
   local_path,
   svn_mkfile,
   svn_modfile,
   svn_copy,
   svn_merge,
   noninheritable_mergeinfo_test_set_up): Move functions to ...

* subversion/tests/cmdline/svntest/mergetrees.py
  (*): .. here.
  Copied from ../merge_tests.py, keeping just the 'generic' code.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1489856 13f79535-47bb-0310-9956-ffa450edef68