Don't hide quickreply with javascript

RFC: http://area51.phpbb.com/phpBB/viewtopic.php?f=108&t=42719

As brought up by DavidIQ in the RFC to change the full editor button to a preview button, having to click a button to show the quick reply editor adds an extra step. You already have to click a button to get to the posting screen, so it's barely any quicker to click a button to display the quick reply. As such, the idea is to simply show the quick reply when enabled, as it is in subSilver2 and when javascript is disabled.