Some fixes for supporting python3

* Fix imports.
* Use python3 syntax.
* Wrap map() calls with list().
* Use list() only wherever needed.
  (Thanks Conley!)
* Fix dictionary iteration methods
  (s/iteritems/items/).
* Make use of sorted() in appropriate places
* Use iterators directly in the loop.
* Don't use .keys() wherever it isn't needed.
* Use sys.maxsize instead of sys.maxint

TODO:
* Make repo work fully with python3. :)

Some of this was done by the '2to3' tool [1], by
applying the needed fixes in a way that doesn't
break compatibility with python2.

Links:
[1]: http://docs.python.org/2/library/2to3.html

Change-Id: Ibdf3bf9a530d716db905733cb9bfef83a48820f7
Signed-off-by: Chirayu Desai <cdesai@cyanogenmod.org>

command.py

@@ -140,7 +140,7 @@ class Command(object):
     groups = [x for x in re.split(r'[,\s]+', groups) if x]
 
     if not args:
-      all_projects_list = all_projects.values()
+      all_projects_list = list(all_projects.values())
       derived_projects = {}
       for project in all_projects_list:
         if submodules_ok or project.sync_s: