Factor namespace functionality into util/network_namespace.py
Add network_namespace.py
Remove unneeded None variables
Whitespace changes
Set state to ALIVE rather than STARTING after forking
Temporary commit b/c this network sux
Revert "Temporary commit b/c this network sux"

This reverts commit 266c11c7811d9ab9f8003a1178f7060dd5ba5f3d.
Add an option to automatically choose an address from 192.168.1.0/24.

Refactor things a bit too, and  beef up the pydoc somewhat.
Factor IP address space management into sts/util. Add convenience option to
specify prefix as /32.
More descriptive error message
Set netns's IP address properly, and generally clean up code.
Allow controllers to be launched in a network namespace
Update README
Separate out raw socket binding from newtork namespace creation
Add TODO: need support for auto sync uri IP addresses
Add ability to bind to pcap (for filtering) rather than a raw socket
Add import guard against pxpcap not being compiled
Update build instruction for pxpcap
Add TODO: sync_port is the *listen* port, not the ephemeral port where data is
sent
Add BufferedPCap objects, which buffer all packets read in a thread-safe queue