Textile parser regression with !! url
In #3209 you added support for excalamation marks in url but it disabled the possibility to do linkable image.
When we arrive at evaluating this re, the input looks like either like:
<p>!/attachments/download/1!</p> <-- we want to expand or <p>http://www.pouet.com/ahah!lol! <-- we don't want to expand
But also like, when we have "p=."
Therefore I suggest to use this re in redcloth3.rb :
IMAGE_RE = / (<p>|<p\s:.*:>|\s|^) # start of line? \! # opening