Review of schema modules [in progress].
Few minor changes to schema, test_schema and test_formats modules
Update affected module following review of util.py and test_util.py.
Validate arguments in schema definitions.
Test for specific OSError exceptions in quickstart.py.
Convert print statements to logger.info() and disable the logger in the test modules.  Modify a few test cases in test_signercli.py that incorrectly compare SIGNABLE objects.
Fixed: quickstart.py left behind a temporary directory.
Started TUF system test.  Prepared test fixtures.
test_system_setup.py is complete.  Few minor stylistic changes were made to download.py and signercli.py.
Added few more methods to test_system_setup.py and some stylistic changes to signercli.py.
Few changes to test_systemp_setup.py.
Added https://gist.github.com/1347055.git as a submodule.
We now *should* verify SSL connections given certificate authorities.
Use file copy instead of a git submodule.
Adding test_rollback_attack.py.
Added test_rollback_attack.py.
Modified test_system_setup.py and test_rollback_attack.py.
Refactored test_replay_attack.py, changes to test_system_setup.py and renamed one of the docs.
Removed doc duplicate and an obsolete test module.
Refactored test_replay_attack.py, test_system_setup.py.  Added replay_attack_setup.py.