Return unicode from _safe_str in Python 2.x

Under *Python 2.x*, `_safe_str()` should return `unicode`, otherwise `logger.error(u"The quiæk fåx jømps øver the lazy dåg")` fails in celery's `ColorFormatter`. This is because celery's `ColorFormatter.format()` expects unicode or ascii from `_safe_str()`, not `utf-8`, otherwise `str_t(...)` (`unicode(...)`) fails.
Updates AUTHOR entry
Fixes typo transports -> transport
Now depends on amqp 1.0.13
Fixed typo.
Updates Changelog
Drop distribute dependencies

distribute was merged back into setuptools-0.7 and deprecated therefore.
Adds Sascha Peilicke to AUTHORS
Updates Changelog
#243: Handle connection errors and channel errors for failover reconnect
flakes
Adds Corentin Ardeois to AUTHORS
Bumps version to 2.5.13 and updates Changelog
Msgpack no longer converts lists to tuples
safe_str tests passing
pyamqp now implements driver_version
Revert patch from #245 and use sys.getdefaultencoding
Bumps version to 2.5.14 and updates Changelog
Encoding tests passing
Updates Changelog