New function-based custom validation mode.
New function-based custom validation mode.

nicolaiarocci/cerberus,brettatoms/cerberus,funkyfuture/cerberus,nicolaiarocci/cerberus,funkyfuture/cerberus,calve/cerberus,MacHu-GWU/cerberus-sanhe,dkellner/cerberus,pyeve/cerberus,calve/cerberus,MacHu-GWU/cerberus-sanhe,pyeve/cerberus,dkellner/cerberus