#33 Add Strikethrough sending support

[ender]

A while back I submitted a patch that added
strikethrough decoding support to GhettoHTML, but I
didn’t think to support encoding it. Duh.

Tested successfully against Adium 0.8svn, iChat AV,
offical AIM/Mac. Oddly enough, 0.7 doesn’t seem to
decode strikethroughs properly, but 0.8svn does even
though I didn’t change anything there.

[ender]

Logged In: YES
user_id=1027166

Just noticed a bug with the patch.. just as well that I
forgot to check the box to upload it the first time.

[ender]

New patch

[Evan Schoenberg]

Logged In: YES
user_id=669684

Oops, forgot to close this after committing it :)

Thanks!