upgrade to Rails 4.0.0.beta1

* starts using strong_parameters, removing `attr_accessible` from models
* wrap all scopes within a lambda
* symbolize all keys for `APP_CONFIG`
* rewrite `wysiwyg_field` to fit into the Rails 4 way of building HTML tags for forms
* replace `update_attributes` with `update`
* remove the uses of `scoped` and `all` when not necessary
rewrite many specs

* use `specify` instead of `it` where it reads better
* remove `assigns()` tests that didn't actually test any functionality (the instance variable tests will be also replaced by full stack integration tests in the future)"
use RSpec's new recommended `expect(...).to` syntax
there are some attributes that may require a list of values

an example of which is box-shadow, which can have multiple values comma-separated (ie. an inset box shadow and an outer box shadow)
bump shoulda-matchers, which allows bourne and mocha to finally update to the latest releases

also update some jQuery plugins
the Routing class is no longer necessary, so let's dump it
start using the RVM 1.19's version of .rvmrc, which is .ruby-version and .ruby-gemset

also do some minor cleanup like no longer requiring Test-Unit and specifying that imagemagick is required in the README
various cleanup

* use CoffeeScript splatting for height fixes
* take advantage of `where.not`
* limit stubbing of STDOUT to only rake task specs