Add ability to pass in an array of IValidator

[ElliottBrand]

Added a parameter to pass in an array of IValidator, so validation can occur on all the provided validators.

[midoriiro]

How do you handle this case: Validator is set with a validator of type IValidator<MyModel> and Validators is set with two validators for specific fields of MyModel ?

My guess is field/model validation in Validator branch will fail with Cannot validate instances of type 'MyFieldType'. This validator can only validate instances of type 'MyModel'..

Can you test this case ?