devel/py-txi2p-tahoe: Add py-txi2p-tahoe 0.3.5

This is a fork of txi2p, to help Tahoe-LAFS project to get unstuck in Python 3
porting efforts.

txi2p is a set of I2P bindings for Twisted.

txi2p supports both the SAM and BOB APIs for I2P. The default API is SAM.

WWW: https://github.com/str4d/txi2p