Adds frontend short statuses support. Admin management to come with next commit

Main idea: going a little further into the POSSE (publish owne site, syndicate everywhere) things, and get mor visibility by being listed as an Indie Web project.

Instead of publishing statuses directly to Twitter / Facebook / something else, we publish them on Typo. A status is a formated, 200 or 300 characters max message. Statuses have a permalink like posts, in a /st/ hierarchy. The permalink start with the status id so we can push the same message twice.
When pushed on Twitter / FB..., we shorten them to the max size of the service posts and add the short URL to the status.

Example:
Posted on Publify:
  permalink: http://myblog/st/1-hello-this-is-a-status
  short URL: http://myblog/shortlink
  message: Hello, this is a status

Posted on Twitter:
  message: Hello this is a status (myblog shortlink)

Statuses are not listed on the main timeline.

Examples in the wild: Tantek Celik (@t) way of doing. http://tantek.com/2013/183/t1/google-reader-dead-answer-integrated-indie-aggregation

Implementation on Typo:
• Statuses inherits from Content using the body field + user's text filter + permalink (this is done and covered)
• Each users with publishing rights can create statuses
• If no Twitter / Whatever account is configured, statuses are just published on Typo.
• Twitter accounts are setup on a per user basis.
• Statuses are displayed on /author/your-name pages
• Statuses timeline is /st/, displayed by th default number of items in a list.

Open questions:
• Should statuses timeline have a RSS/Atom feed?
• Should we cache the user avatar or load it from Twitter?
• Push on a per status basis?
• Is it already lunch time?
Adds a hack to allow theme creators to bundle gems with their theme when needed.

This won't hurt anyone and I'm really fed up with having constant Gemfile conflict because my theme needs hpricot to run.
First attempt to give Typo short messages capability. See commit e7b1331 for more information and specs.

TODO:
* add Twitter integration.
* add RSS / Atom support
* add to the sitemap (option?)
* allow to use an alternate domain name for URL shortener (???)
* refactor, add more tests (it's almost 40ºC (100ºF) here so finding time to code should not be that difficult).