This primarily moves a lot of things around to enable tox. Some things here: * add ./tools/install-deps this allows easily installing dependencies to build or run tox (the openstack libraries require some c python extentions so you end up needing python-dev and such in order to run tox).
* add tools/create-gpgdir and tools/sign-examples this just moves that logic out of Makefile to these places.
* make tools/js2signed only re-create .sjson and .json.gpg files if the .json is newer. It supports '--force' to disable this logic.
* move to using flake8 instead of pyflakes and pep8 (flake8 uses pyflakes and pep8)
* debian/control drop python-glanceclient and python3-keystoneclient these aren't available in trusty and thus can't build if they are there. Also adjusted tests to skip these if not present.
* split signjson_file out of toolutil as toolutil required distroinfo which is only needed by make testdata.
* add a trusty-flake8 tox environment for testing versions of flake8, pep8, and pyflakes that are on trusty. This allows us to catch what would be trusty specific build failures in tox.