exception handling adapted
added future lib to dependencies
replaced xrange with future.range
replacing map with the one provided on future
reducing a bit the types-offer in favor of portability. Future.str is what we support now instead of python2.str&python2.unicode. This means that all basestring stuff is been removed as well
fixed non-deterministic repr of ObjectSchemas
de-hardcoded repr on test
fixing last failing tests (byte string made unicode prefixing u, and removed basetring, and invoked next(thing) instead of thing.next()
in-code documentation with updates re str/unicode support on different py versions
Merge branch 'python3-support' into develop