model: added methods() and call() method

methods() and call( works the same way as Meteor.methods.

Add methods with modelInstance.method({something: function(){}})
Call with modelInstance.call('something', function(err, result) {});

Essentially is just a wrapper that adds a namespace to a Meteor method
account / user: move account logic into user package

Using Model.call() methods to insure that user methods are run on both the client and the server, ensuring that a malicious user isn't causing mayham.
collection-plugins: createdAt should not be modifiable from update.