Trio programming (Troy, Sarah, German) - added framework for SharedPreferences for login.activity; need to get onClickListener working with verifying input data from login screen
Implemented sharedpreferences so that it saves that the user is logged in so that when they exit the app and come back they don't have to log in again; added alert dialog for invalid credentials
Added checkLogin function to homescreen to verify that user is still logged in; if so, when user hits back to go to login screen, they are immediately put back to the homescreen since they are already logged in, which is stored in sharedpreferences
Added clearData method for logout to delete shardprefs; removed toast message popup (used for testing purposes to ensure that sharedprefs info was deleted)
Merge pull request #14 from german92/develop

Develop