Added daoFactory.findOrInitialize(params, defaults)

This functionality acts pretty much the same way as
daoFactory.findOrCreate except you don't actually create the record,
Sequelize would only .build() it. beforeValidate/afterValidate hooks
will still run in the same manner as findOrCreate().

This functionality was inspired by:
http://guides.rubyonrails.org/active_record_querying.html#find-or-initialize-by