Dynamic where rules

[leitom]

Allow for dynamic where rules example:

'email' => 'exists:staff,email,account_id,1'

rule will be: 'email' => 'exists:staff,email,account_id,{account_id}’

via ->validate($formData, [‘account_id’ => 1]);

[leitom]

This is not needed for laravel 4.3 because of the request classes, but for every one prior to 4.3 this could be handy.