Fix show taken/passed

Fixed bug where the taken and passed fields in the Details Fragment wouldn's show the right value, but "false" or an empty string.
Add last update information.

Added information towards the last update date and time to the preferences screen.
Add About dialog.

Added about dialog, with external fragment added from everywhere else
Add english translation. Remove temp files.
Removed temp files from strings.
Remove unused strings. Remove app language option.

Removed the unused strings by lint. A few are left, probably for future use.

Removed the option to change the app language. Now it only changes the record option. It is not the Android way.

Will have to take a look into "supporting unsupported locales"
Various fixes.

Fixed language change. Now actually works.
Fixed language string. Now shows it is the Record language and not the app language.
Fixed DNI failure where a lower case letter would not pass even if it was correct.
Fixed last update string when going from the login screen without any downloaded data.
Rearranged strings location for clearness.