Bump po6 to 0.6
Generate test tarballs
Macaroons for authorization

TODO:  provide a narrative to go with the code examples.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Makefile.am
	bindings/python/hyperdex/client.pyx
	common/datatype_info.cc
	common/hyperdex.cc
	include/hyperdex.h