Add -v and -q options to mergeinfo for use with --log.

* subversion/svn/svn.c
  (svn_cl__cmd_table): Allow -q and -v to be used with mergeinfo.

* subversion/svn/mergeinfo-cmd.c
  (svn_cl__mergeinfo): Prevent -q and -v from being used without --log and
    pass their state to mergeinfo_log().
  (mergeinfo_log): Where the rubber meets the road, do what's needed to
    make -q and -v work.

* subversion/tests/cmdline/log_tests.py
  (mergeinfo_log): Add tests for -q and -v. 
  


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1548257 13f79535-47bb-0310-9956-ffa450edef68