use python 3 print syntax

(with from __future__ import print_function for 2)
port c glue to python 3 and keep python 2 support
support python3 binary while working with pytohn2 str
port edsig to python3, keeping python 2 support
make tests work in python 2 and 3
add travis coverage for 3.3 and 3.4
fix python 2.6 (sys.version_info is tuple)
make setup.py speed work with python 2 and 3
Update README to include python 3 versions
Merge branch bit/py3 (add python3.3/3.4 support)