[dev] Additions to Help.php

[Max Kalika]

I'd like to add some formatting handling functions to Help.php.  I have it
working locally with <b> and <i> tags, but Chuck suggested an alternative
on IRC (that couldn't read because gaim was interpreting things when it
shouldn't).  Anyone have comments/objections/suggestions for other
formats/tags (i.e. img)?

I'd also like to prefix all the handlers with _ because they're really
private. Any objections?

--mk