Replace javascript:; links with buttons.

Created by: cirosantilli

Behavior improvements:

• middle click on the button does not open a javascript:; tab
• on hover browser does not show the link destination javascript:;

Appearance changes: none.

Also more semantic: links exist to redirect your browser somewhere else. This explains the better behavior.

Works because button.btn type="button" and a.btn are styled almost exactly the same in Bootstrap.

Just for reference, the elements that are affected are the "Reply" button and the "+" on diff comments: