Image Board sample working

Addresses issue #1 

Changes:
 - Replaced mongo.ts with an up-to-date mongo.d.ts
 - Changed connection routine in db.ts to connect properly
 - changed MongoDb version to a recent version compatible with the d.ts
 - Changed express version to use only 3.x versions (will need more work to suport 4.x)
 - Fixed some Jade syntax