Updated validify() function

Made several changes:
- All events attached by this function are namespaced with `.validify`
so that all these related events can be removed just by using
`.off('.validify')`
- The classes and regex patterns in the options have been revamped into
Object arrays containing key-value pairs. This is so that you can add in
your own classes just by extending the options, without having to go
into the function itself.
- Other little tweaks to be less verbose