flight-collection.js: Extracted generic slCollection module
flight-collection.js: Converted length attribute to function

Apparently the length attribute confused jQuery and prevented the use
of the event framework on the collection.
flight-collection.js: Trigger 'add' event after a new object is added
flight-collection.js: Moved slFlightCollection to flight.js
flight-collection.js: Renamed to collection.js
Merge pull request #32 from Turbo87/collection-js

collection.js