Fixed a couple Newuser issues

BMInterfaceNewuser now verifies that username and email address are
acceptable lengths, the UI limits the length of those input fields, and
the form is hidden after you're done with it.
Fixed indentation
Merge remote-tracking branch 'upstream/master' into 728_555_account_creation_issues
Restored email and constantized field lengths
Merge pull request #853 from AdmiralJota/728_555_account_creation_issues

Account creation validation and form-hiding