Fixed some warnings
Classes use specifically use application context where applicable for safety reasons
Added method to Prefs to return application context
Added comments to populator class and margin to bottom of requirement groups
Fixed padding looking bad in checksheet fragment
Fixed XML parser test
Added warning about clearing prefs to PrefsTest
Changed checksheet load task to avoid passing Context and instead use application context provided by Prefs
Added a bunch of comments to explain what code is doing
Added GUI test case, only checks welcome screen right now