Modqueue: add reply button to comments

[A suggestion][0] from /u/rotorcowboy.

`printablebuttons.html` contains logic that supresses the reply button for
comments that show up on profile pages.  This appears to have incidentally been
included for the modqueue, per 0fe8f70 and prior code, so I just removed it and
massaged a few other things to make everything work.

This also adds comment reply capabilities to the various modqueue-like subpages
(reports, spam, edited).

[0]: http://www.reddit.com/r/ideasfortheadmins/comments/2ju3dg/add_a_reply_button_to_comments_in_the_modqueue/