imgur fix, + imgur gallery support

hi, 

Is this how you as to merge changes? 

imgur now has 5 and 7 char hashes. The regex was only looking for 5 chars, i fixed it so it now looks for 5 or 7. 

I also added the ability to embed imgur albums in discussions. 

Here's what it looks like (the bottom three): http://128.199.254.7/bbs/index.php?p=/discussion/11/test