Added singleton Connection class for the coming-in-a-bit semaphores exercise.
Some dummy work into Connection connect() method.
200 connections running, take that
Using Semaphore to limit number of simultaneous connections to 10.
12. Semaphores: always remember to call release() in finally block.
Slight change in the Semaphore constructor: added fairness paramather set to true, which means whichever thread called acquire() first will be the first to get a permit when it's available. some performance benefits with false?.