Usability: Relocate Comments text box button adjacent

This is a follow-up toJENKINS-6659. Nice to to see the ability to annotate the change is now in place.

However, a lot has changed in the UI since the issue was raised back in 2010. The top right corner lcoation for the box seems out of place and could be overlooked.

From a usability perspective, it would be preferred the text box float alongside the Save / Apply button.

From a compliance perspective, a Global setting

[ X ] Job Config History comments are mandatory

would be a nice option, such that the Save / Apply is not active until a Comment is entered.