fixes #11862 - validating that casted hash is valid

Catch parse errors correctly under Ruby 1.9.3, and ensure the uncasted
value is displayed back in the UI if it fails to parse.

Fixes #12343 - Fixing parameters caster for boolean values

Fixes #12078 - list validator in smart class parameters validates any string coercible value

fixes #10232 - moving validations and casting out of lookup key and value