[#470] Fix: load_missing_contant

Not 100% sure why we were patching this core active support class, but it seems unnecessary at this point, and since we aliased it without implementing it, I can see why it might have failed.
[#88] Use Paperclip for attachments

* Bring in initial Scenarios from Assets
* Add test files
* Add new fields to attachments table
* Pull in updates to Attachment
* Add attaching
* Integrate attaching
* Make Image/File blocks use has_attachment
[#470] Candidate fix for Ubuntu loading issues
[#470] Remove a likely no longer necessary core rails override
Fixing most of the tests.

* Stack trace of unexpected errors that occur during content block creation is now readable: Happens most often if there are logic errors with blocks). 
* Unexpected errors during block creation should always reshow the form. 
* Basic file uploads work for images/blocks
* Upgrade FactoryGirl to 3.0
* File blocks can now be created/viewed from UI
* Fixed some functional tests
* Fix issue where '#create' methods were not being called on controllers
* Uploaded files paths are sanitized correctly. Blank paths are not altered.
* Remove Enginecontroller hacks (seem to be unnecessary for now)
* File/Image blocks now correctly enforce that path is a required field.
* Verify that adding an image works.
* Verify archived files are not displayed to guests.
* Remove duplicate functional tests
* Ensure reverting test 'fails' rather than errors.
* Ensure correct behavior on redirects for users to cms subdomain.
* Fix issue where attachments were not being updated.
* Document some problems with Versioning/Publishing API that require work arounds
* Refactor broken tests
* Simplified versioning and attachable tests to clarify the actual current bugs.
* Convert reverting images from broken functional test to passing cucumber scenario.