shorten up the redirect

The redirect is currently pretty long.

http://example.com/mailcomment/redirect/%3C19.12054.0.1267177300.25313ee...

As a first simple proposal I think we can replace "redirect" with just the letter "r" or the word "go"

http://example.com/mailcomment/r/%3C19.12054.0.1267177300.25313ee3c3614b...

A next step could be to shorten mailcomment to something like "mc" or combine it with the "redirect" like:

http://example.com/mgo/%3C19.12054.0.1267177300.25313ee3c3614bc2162ca0e3...

A more drastic step would be to create a uniqueid that we store in the database and use to identify the proper token.

http://example.com/mgo/123456/mgo

+----------+---------------------------------------------------------------------------+
| id       | value                                                                     |
+----------+---------------------------------------------------------------------------+
|   123456 | %3C19.12054.0.1267177300.25313ee3c3614bc2162ca0e3fd6501d2%40example.com%3E|
+----------+---------------------------------------------------------------------------+

That would also make the regex that finds the token much simpler.