LoginRegister

Finally completed this overly due issue :)

This branch provides a clear and separated Login and Registration process (absolutely necessary with exactly these fields because of our plans as discussed with @AlexanderGuetler). 
Registration includes gender, birthday year & month, country, email (should also fix #554), username & password.
An E-Mail field is also added to the Login Dialog.

testrun:
http://jenkins.catrob.at/job/Catroid-Multi-Job-Custom-Branch/155/
(testAddNewProject failing randomly? I've nothing changed there).