Update Feb, 7: 0.13.3 released

This release adds a new experimental gevent.httplib module that implements httplib-like interface on top of libevent http client. It also fixes a number of issues. Read the full changelog for details, get it from PyPI.

Thanks to Tommie Gannert, Örjan Persson, Alexey Borzenkov. Ralf Schmitt, Nicholas Piël, Elizabeth Jennifer Myers, Ned Rockson, Jon Aslund.