[sugar] Feature/string freeze exception: Feedback for registration

[Simon Schampijer]

Hi,

it has been requested that we add to the current release a new feature
after the freeze: Feedback for registration

After eben's suggestion we have implemented an alert that is displayed in the home 
view that gives if information if the registration with the schoolserver failed or 
not. The code has been reviewed as well.

http://dev.laptop.org/ticket/6136

It contains some new strings - that is why i ask as well for this exception.

Best,
    Simon