Refactoring complex methods of class Register

[santiago-a-vidal]

Related to no particular issue. This is a behavior-preserving refactoring.

Summary of this pull request:

• We are evaluating a research prototype called Bandago that assists in the refactoring of complex methods. Bandago is an Eclipse plugin that automatically identifies and refactors a type of code smell called Brain Method. A Brain Method centralizes the intelligence of a class and manifests itself as a long and complex method that is difficult to understand and maintain We have applied Bandago to 2 complex methods of your project, and we would like to receive feedback.
• Bandago is very conservative and you should not observe many source code changes (only in the affected class).
• The source code (after the refactoring) should behave equivalently to the original one.
• As a sanity check, we have run tests before and after Bandago performed the refactoring(s) on the project. All tests passed.
• The goal of the refactorings applied is to improve the legibility of the refactored method.
• In this case, Bandago refactored the method Register.save extracting fragments of its code into the new methods sendActivationMailIfNeeded, and retryActivationCode. Also, the method Register.myValidate() was refactored extracting fragments of its code into the new methods checkOpenID, checkUsername, and preserveUsernameAndPassword.

Thanks in advance for your help in this evaluation!