1) Removed potential memory leaks & added destructors for all classes.

2) Changed the number of redundant ACKs being sent to vary based on ACK size.
3) Libpcap loss at the sender is now handled - by sending packet sizes and
send times in the packets and having them echoed back in ACKs. Reordered
ACKs are detected as being seperate from libpcap loss and are ignored.
4) updated the plot creation python script to give out loss, maximum delay graphs.