e107 v5.2.1

- Fixed bug in class2.php stopping some users from defining HEADERF correctly - Fixed bug in /plugins/log2.php where broken image was shown on first visit to page - Fixed chat.php bug (where did that come from again??" - Added avatars - NOTE, no avatar images are supplied with this version for copyright reasons - I'm hoping to have this sorted by next release. To use avatars, you need to upload your avatar images to themes/shared/avatars. - Included revised theme.php and style.php for e107 theme showing commentstyle and chatboxstyle code. The commentstyle code show how you can have avatars in comments, chatboxstyle is just an alternative way of displaying chatbox text.