Lab2 - ProxyServer

Classes:

====ProxyServer====
Handles new socket connections, if there are less than the max
threads, it passes the new connection to the ConnectionHandler

====ConnectionHandler====
Utility Static class that checks if the received connection exists, if it does, 
the handler does anything because the open connection will intercept.
If the connection is new, create a new TCPconnection and a new thread to handle it.
With every new connection that arrives, the thread queue checks and closes
timed-out connections that have been open too long.

====TCPConnection===
Runnable class, parses the input stream from the socket and verifies if its a 
proxy request (to the web) or an inner request (to logs or policies). 
If its a proxy request - the thread validates its legality, and transfers
the request/response data between the client and the host server.
Once the request has been fully handled, a timeout is opened on this connection
(only if there is a keep-alive).