fixes #2260 Allow ERB in ENC global / class parameters

Adds code to parse the global & class parameters, and adds a setting (default true)
 to disable this if needed. Also has some tests.
fixes #2989 - missing fields in host API output (API v1 and v2)
fixes #2969 - remove all legacy api code in UI controllers
fixes #2985 - remove #as_json method from AR models since rabl views used for API
fixes #2986 - remove #show method from controllers and routes.rb when not used
fixes #3052 - reports#show json rabl template to match as_json output that was removed
fixes #2969 - add deprecation response for api calls to UI routes