Extract buildEventsFields function
Rename buildMessage() to sendMessage()
Transport classes are now instantiated, refactor EmailTransport class
Create getEventSetting() and getTransportSetting()
EmailTransport now extends Transport class
More explicit variable name
Remove some console.log and comments, add comments
Major refactoring, add TransportEventHandler class

- add TransportEventHandler class
- add Transport.buildMessage() method
- sendMessage() now takes a callback as last parameter
Add schema.method("notify") to Mongoose plugin
Add some comments, extract getTransportName() method
Push version to 0.1
Merge v0.1 from branch 'develop'