[JRO] Delete all the things

Most of this code has been moved to jayroh/thredded_gem. Some of this is
old cruft and needs removing.
master's schema
WIP. Gemfile updates and move around messageboard tables

The first table to play musical chairs is the messageboards table.
It's been renamed to thredded_messageboards and the "new" engine table has been renamed, temporarily to "new_thredded_messageboards" so it can stick around for reference.

* Remove Pseudohelp.
* Remove messageboard and topic helpers from the Application controller
[WIP] DELETE ALL THE THINGS (sorta) & migrate data
[JRO] Hide header for now
[JRO] Move private topic data

* Rename the `type` STI column in topics to Thredded::PrivateTopic
* move the private_users table to thredded_private_users
[JRO] WIP. User registration functioning

* Style updates to get private topics looking normal
* Remove board-specific form elements from the user registration form
* User profile page showing latest topics

TODO: Create a mixin to allow someone mounting the engine access to
common data like `thredded_abilities`.
[WIP] Scrolling changes & miniprofiler tweaks

Hook into an arbitrary dom node with the latest read data, not just the
body tag.

Rack::MiniProfiler should skip static assets when it profiles. Only look
at the rails app's paths.
[JRO] Start upgrading to Rails 4

LOTS of deleting. GREAT times

compass and sass is kinda fucked but ... w/e
[JRO] Delete more & get sass, compass to work

* upgrade all gems where needed - mostly compass related libs
* clean up gitignore
* delete specs and mailers left over from before extraction
[JRO] Upgrade devise for Rails 4
[JRO] Replace font-icons with font-icons-rails

font-icons has a dependency on compass, no rails hooks, and has been troublesome so this replaces that with font-icons-rails.
[JRO] Update secret_token

Rails 4 adds config.secret_key_base and warns when it doesn't exist.
[JRO] User updating and viewing passing

Removing messageboard-specific code from registration controller and
getting to work with strong params
[JRO] Oauth spec passing