Get specs passing with latest versions of extension gems

* Get specs passing with latest versions of
    * ActiveRecord  4.0.4
    * ActiveSupport 4.0.4
    * MongoMapper   0.13.0
    * Mongoid       4.0.0
    * ActionView    4.0.4
    * Ripple seems to be abandoned so no changes made.
* Clean up ActiveRecord setup:
    * Creating tableless AR objects seems even trickier in Rails 4 so
      simplify testing setup by using an in-memory SQLite DB back-end.

Conflicts:
	spec/ext/active_record_spec.rb
Furthers spec fixes. Still two pending