 - lang 'shoutbox archive' to 'archive'
 - removed 'forced' attribute from main loop
 - registering archive browsing activity
 - corrected settings descriptions
 - "@" username call (compatible with DVZ Mentions)
 - minor visual fixes (increased .thead padding, .thead 'font-weight:bold' replaced with <strong>)
 - replace dvz_shoutbox::member_of($groups) with is_member($groups)
 - default avatar changed from '.gif' to '.png'
 - compatibility set to 18*
 - extended API [custom callbacks for events]
 - code cleanup [PHP >= 5.4]