Fix issue #4329 'automatic merge uses reintegrate type merge if source is
fully synced'.

* subversion/libsvn_client/merge.c

  (operative_revs_receiver): New svn_log_entry_receiver_t.

  (find_last_merged_location): Add new svn_client__pathrev_t argument
   tracking the target.  If the target's mergeinfo shows that a previous
   merge has been performed from the source to the target, then use
   svn_client_mergeinfo_log2() to determine if there are any inoperative
   revisions younger than the last merged location determined strictly by
   the target's mergeinfo.

  (find_base_on_source,
   find_base_on_target): Update calls to find_last_merged_location().

* subversion/include/svn_client.h

  (svn_client_mergeinfo_log2): Add new limit argument similar to that in
   svn_client_log5().

  (svn_client_mergeinfo_log): Doc string tweak to reflect change to wrapped
   API.

* subversion/libsvn_client/deprecated.c

  (svn_client_mergeinfo_log): Update call to svn_client_mergeinfo_log2.

* subversion/libsvn_client/mergeinfo.c

  (filter_log_entry_baton_t): Add new members to implement new limit
   argument to svn_client_mergeinfo_log2().

  (filter_log_entry_with_rangelist): Stop calling wrapped log receiver if
   limit has been reached.  Note: This is fairly ugly because *this* callback
   is still called for all the remaining ranges!

  (logs_for_mergeinfo_rangelist): Add new argument tracking the LIMIT arg
   to svn_client_mergeinfo_log2().

  (svn_client_mergeinfo_log2): Implement new limit argument.

* subversion/svn/mergeinfo-cmd.c

  (svn_cl__mergeinfo): Update calls to svn_client_mergeinfo_log2().

* subversion/tests/cmdline/merge_automatic_tests.py

  (effective_sync_results_in_reintegrate): Remove XFail decorator and tweak
   comment re failure status.

* subversion/tests/cmdline/merge_reintegrate_tests.py

  (reintegrate_with_subtree_merges): Expand test to cover issue #4329.