Using the warning method of Parameterized objects as appropriate
The repr now shows all parameters of the object, including defaults
Minor printing fix for review_and_launch
Now offering metaparameter repr at that start of review (when available)
Now allowing empty List objects and fixed empty Args() behaviour
FilePattern no longer generates a warning if empty
Making sure CommandTemplate finalize method is called in QLauncher
Renamed 'arg_specifier' parameter to 'args' in Launcher
 Renamed 'command_template' parameter to 'command' in Launcher
Renamed 'launch_repr' key in info file to 'launcher'
Optional vcs_metadata helper function added to __init__.py
Updated dictionary keys for vcs_metadata and fixed hg version command