Controller to perform small Ajax utilities.

Such as, in this case: ensuring the text you want to encode as a
field_code is encoded as it would be in the Rails app.
Custom fieldcodes for form fields.
Add field codes to CSV dump.
Don't alter a field once it's been altered, even in live view.
WIP: drag/drop existing element.
Colouring form controls a bit better.
Even more page headers and tabs.