Removed hack which ensures at least 10% of lost packets gets detected by
congestion control algorithms (through the packetDrop event).

Fixed CUBIC congestion, minimum congestion window is 2 allowing for
better packet loss detection.

Cleaned up tcp_processPacket function, separate function for processing
data and processing ACKs.
track shadow process resource usage

we need to make sure that new topologies we generate stay under
our desired memory limits.

refs #194
Merge pull request #197 from jdgeddes/master

Fixed TCP congestion control, no longer relies on packet drop event hack.

refs #194
_packet_getString should be static

refs #194
updated shadowtor topologies for updated TCP stack

closes #194
bump to 1.9.2