Edit policy page

[bdzim]

See #40 for all available policies. This page will allowing editing a set of policies. There are a large number of policies and it would be foolish to create django forms containing all of them. Instead I envision configuration files that list all policies and there types. This can then be used to dynamically generate the forms.

[['LaunchMinimzedAtStartup', 'boolean'],
 ['ShowSplashScreenAtStartup', 'boolean']
]