Add test case for autolink, sanitize link display.

All links are now unquote before displaying, this is to transform
a URL-quoted link into human-readable formatting for displaying:

  x http://th.wikipedia.org/wiki/%E0%B8%A3%E0%B8%96%E0%B9%84%E0%B8%9F
  o http://th.wikipedia.org/wiki/รถไฟ

This commit also fix failing test due to autolink incompatibility
with thumbnail appending which moves autolink to be done inside
paragraph loop instead of outside.

Test cases also updated accordingly.