Feature Request: Strong Parameters Support

This is a feature request for a feature that actually exists in Ruby on Rails so I do not take full credit for it by any means but I think it is a great feature that every framework should have.

Currently in a grails controller there is the `params` variable of type `GrailsParameterMap` (potentially typo).

This Parameter Map should have a property on it `isStrong()` `setStrong()`.

This property should default to false but `DataBindingUtils` should set it to true when binding it over into a Grails GORM Class.

A new setting in config should be made to `requireStrongParameters=true`. If this is set to true and a user does something like

`new Book(params)` It should throw a `StrongParametersRequiredException`. This can help ensure someone doesn't send invalid parameter maps into a Book..

Some people may say to use `CommandObjects` for this but this is heavy, not free unlike some of the guides provided by OCI especially in large projects because of ReflectionOverhead from Spring. It's also, most of the time, a hassle. By providing this default security mechanism we can help save developers from making security holes in their projects.

Start by tracing GrailsParameterMap and DataBindingUtils to understand how params are bound into GORM classes. Then inspect configuration handling and the behavior of new Book(params). Done would require a decided design for the strong-parameter flag, the requireStrongParameters setting, and StrongParametersRequiredException, plus coverage for the binding and rejection cases.

Written by the indexing model from the issue text.