Massive string cleanup for the translation.

I moved some hardcoded strings to the strings.xml file & i've renamed some of the strings to make logic and a clean overview.
Replaced Toast with Crouton and removed the "Account OK" string.

If the username and password is ok it will take you to the home.java...so the Toast wasn't necessarily.
Merge pull request #109 from ratan12/String_Cleanup

String cleanup for the translation.