Fix catalog/thread parsing errors

Thanks to moot for actually updating things in the last 7 months.
Fix backlink parsing

Not sure how that ever worked, I must not have
tested that...
Remove posting functionality

Pretty sure it doesn't work anyway, and I
don't care enough to keep it working.

For now, just disable extension when you
want to post.
Remove read-status feature

Was causing issues with running out of
local storage space.
Remove thread/post hide functionality

I pretty much never use it.
Remove non-working report button

Apparently I removed the reportform a while ago.
Update readme

I had DOS line breaks in there this whole time? gross.