Fix two errors in how a single-file merge stops if there conflicts.  (1) It
didn't abort if there were conflicts on the last sub-range of a non-last
requested range.  (2) When aborting with conflicts it recorded mergeinfo
describing only the current sub-range, not the sub-ranges merged before the
conflict.

* subversion/libsvn_client/merge.c
  (do_file_merge): Take an 'abort_on-conflicts' flag and use it so that we
    abort on conflicts in all but the last sub-range of the last specified
    range, just like in do_directory_merge(). Record the right mergeinfo
    when aborting.
  (do_merge): Pass that flag.

* subversion/tests/cmdline/merge_tests.py
  (conflict_aborted_mergeinfo_described_partial_merge): Test more cases.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1441810 13f79535-47bb-0310-9956-ffa450edef68