Registration Steps Improvements

1) Registration form should be in a box, just like the Login.

2) After I press "Register" button, I don't want the message "X X (X): Registration successful" to be displayed, but instead I want to be automatically logged-in and redirected to Main.

In the current version:

• I am a new user on Main page
• I press Register, and fill the fields
• after the register, I need to press "Login" link in top corner
• fill the fields, press "Login" button
• I will be redirected to the "XWiki.Register"
• I will press the logo or the breadcrumb to get to the main page, but if I'm a beginner user I might not know how to get to the Dashboard / Main page again.