* url in question /%EF%AC%81?foo=bar&bz=%AC%81
* This is a unicode character, which can't be decoded from
ascii. Jinja templates will handle this if it's unicode, or if it's
hex encoded ascii, but can't take a non-unicode string in python 2 and
put this in a template.
* The querystring was being quoted, which is incorrect, as:
  1) the special characters in the query string mean something
  2) The rest of the querystring is already quoted. This makes it
  double quoted, as seen in the datastore file
* We don't want to unquote urls before putting them in the template
anyway.
* There was s further error passing this unicode path to the template
resolution, where in posix path, it fails:
```
File '/usr/lib/ckan/default/lib/python2.7/posixpath.py', line 73 in join
  path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 1: ordinal not in range(128)
```
The solution here is to make sure it's unicode passed into the
function.