pull: all pass along extra opargs

Wihtout this patch, commands.pull silently drops opargs defeating the whole
purpose of the argument.

mercurial/commands.py

@@ -5312,6 +5312,7 b' def pull(ui, repo, source="default", **o'
                         "so a rev cannot be specified.")
                 raise error.Abort(err)
 
+        pullopargs.update(opts.get('opargs', {}))
         modheads = exchange.pull(repo, other, heads=revs,
                                  force=opts.get('force'),
                                  bookmarks=opts.get('bookmark', ()),