Update requirements.txt

Add socksiPy-branch for Tor support

Create tor_util

Tor utility library - contains various functions to support Tor in OpenBazaar

Add preliminary native-Tor support for zmq
Rename tor_util to tor_util.py

Doh

Changes required for Travis build

explicit socket imports mostly

Replace wildcard import with explicit class name

Remove unecessary print and whitespace

Whitespace removal and change print to log

fix imports and name reuse

Final change to keep Travis happy, specify excepts

Remove generalproxyerror exception