Sketch of #201.
Merge forward and stop mis-using PortMap.
Typos.
Add docs.
Fix failing test.
Unicode!
Oxford comma
Merge remote-tracking branch 'refs/remotes/origin/master' into config-internal-links-201

Conflicts:
	flocker/node/__init__.py
	flocker/node/_config.py
	flocker/node/_deploy.py
	flocker/node/_model.py
	flocker/node/test/test_config.py
	flocker/node/test/test_deploy.py
	flocker/node/test/test_model.py
Merge remote-tracking branch 'origin' into config-internal-links-201

Conflicts:
	flocker/node/_config.py
	flocker/node/_deploy.py
	flocker/node/_model.py
	flocker/node/test/test_config.py
	flocker/node/test/test_model.py
Factor out parsing of links.
Parse an link alias.
Don't create internal links.
Remove application from links.
Docstring.
Slightly better documentation.
But remove docs, since this isn't actually usable yet.

That is, we just parse the config but don't do anything with it yet.
lint
Address review comments.
Better repr test.
Add some type checking.