Update the management command to use argparse for Django >= 1.8

[mwhansen]

Since django.core.management.runserver.Command doesn't have option_list in Django >= 1.8, the devserver command does not have the --noreload option causing autoreloading not to happen. This pull request makes devserver use argparse in Django >= 1.8.

[ShipraShalini]

@mwhansen I cannot run it with the changes you have made.
It says AttributeError: type object 'Command' has no attribute 'option_list' at line 47 (for backwards compatibility).
If catch the Exception, i get TypeError: 'Namespace' object is not iterable in run_from_argv.