osc branch reads project/package in package directory

The osc branch (withouth arguments) is able to read the project/package
from current package dir and use it.

NEWS

@@ -2,6 +2,7 @@
   - add size limit mode, files can be ignored on checkout or update given a certain size limit.
   - --csv/--format options for results command - using format user can explicitly specify what he wants print
   - support for "unresolvable" state of OBS 2.0
+  - osc branch reads project/package in package directory
 
 0.126
  - added VM autosetup to osc. This requires appropriate OBS version and build script version.

osc/commandline.py

@@ -1677,6 +1677,7 @@ Please submit there instead, or use --nodevelproject to force direct submission.
         if nothing else specified.
 
         usage:
+            osc branch
             osc branch SOURCEPROJECT SOURCEPACKAGE
             osc branch SOURCEPROJECT SOURCEPACKAGE TARGETPROJECT
             osc branch SOURCEPROJECT SOURCEPACKAGE TARGETPROJECT TARGETPACKAGE
@@ -1694,8 +1695,12 @@ Please submit there instead, or use --nodevelproject to force direct submission.
             # python has no args.unshift ???
             args = [ conf.config['getpac_default_project'] , args[0] ]
             
+        if len(args) == 0 and is_package_dir('.'):
+            args = (store_read_project('.'), store_read_package('.'))
+
         if len(args) < 2 or len(args) > 4:
             raise oscerr.WrongArgs('Wrong number of arguments.')
+
         expected = 'home:%s:branches:%s' % (conf.config['user'], args[0])
         if len(args) >= 3:
             expected = tproject = args[2]