Begin update to Ruby 2 and Rails 4

Update the ruby-version (replace .rbenv-version with .ruby-version)
Update to Rails 4.0.0 in Gemfile and bundle update to update everything
to the latest stuff. I'll specify version ranges when I get everything
working.
Require gems from Gemfile for the current environment
Remove whiny nils config and explain query setting
Specify versions for sass-rails, less-rails and coffee-rails
Set eager_load to true in prod, false in dev and test
Remove references to model-based mass assignment protection
Update simple_form to master which is Rails 4 compatible
Update routes and controller actions for Statements

My old routes didn't work with Rails 4, and they actually didn't make a
lot of sense. Not sure what I was thinking. Really what I have is a new
statement form and a create statement action which just directly renders
it's result since it's not being saved in the db and given an id to be
pulled up later.

I haven't tested this change, but I'm guessing it will work. Need to
test.
Use secret_key_base instead of rails secret_token
Replace attr_accessible with strong params
Install bootstrap static assets instead of the LESS versions
Remove less-rails from Gemfile since it's no longer used
Refactor User types from methods to constants
Refactor date range stuff to work even with no contributions
Update link to new path for statements new view
Use blocks for default_scope
Use all instead of scoped
Add money-rails gem. (Remove unused newrelic gem).
Set Money's default currency to USD
Add amount_cents column and migrate existing amounts to that column.

Moving from using decimal type to integer along with money-rails.