[Feature request] Add formType option to custom action

[ksn135]

IMHO, it's great to extend s2a to automatically call createForm and renderView on custom action if option formType is set and after that call validation to check user input.
For example we call decline action, and form is checked for not blank reason field.
All fields and validations are defined in special formType class specified in options.

[sescandell]

I think I see what you mean... Until now, I managed these case "manually" using normal Form creation (with AJAX and so on for example)... Let's discuss about that for a next release.