Add the ability for svnmerge.py to pass --username and --password options to the 'svn' command-line binary.
Add the ability for svnmerge.py to pass --username and --password
options to the 'svn' command-line binary.

* contrib/client-side/svnmerge.py
  (launchsvn): Handle "username" and "password" options from opts,
   adding them to the command used to invoke 'svn'.

  (global_opts): Add OptionArg objects for "-u"/"--username" and
   "-p"/"--password".

Patch by: Paul Cook <pcook@caltech.edu>
(Tweaked by me.)

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion