Login link tries to activate the first textfield once the colorbox opens... but comments use the same ID and grab focus

On most pages the login link in colorbox works great. But on pages that have comments enabled and the form inline, it finds the Comment "name" field instead. this is because both the Comment "Name" field and the colorbox login form "username" field have the same id="edit-name".

I've attached a patch that fixes the problem. It simply changes the ID of the login field to "cbox-edit-name", and updates the JS to highlight that field instead. I also updated the id of the password field to "cbox-edit-pass", because it seems like good practice to identify it as colorbox specific as well.