Add short options for git cl presubmit

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 08ea2a313411d3c84d5bbc53c97b7c7ded7e9d66..aba28f6746c3e40a95a1e674156f8ce3982c02c1 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1053,9 +1053,9 @@ def CreateDescriptionFromLog(args):
 
 def CMDpresubmit(parser, args):
   """run presubmit tests on the current changelist"""
-  parser.add_option('--upload', action='store_true',
+  parser.add_option('-u', '--upload', action='store_true',
                     help='Run upload hook instead of the push/dcommit hook')
-  parser.add_option('--force', action='store_true',
+  parser.add_option('-f', '--force', action='store_true',
                     help='Run checks even if tree is dirty')
   (options, args) = parser.parse_args(args)