Move commands into their own 'api' module
Rename 'jspot.potter' to 'jspot.pot' to be more consistent with 'jspot.json'
Use defaults in api
Store defaults in a single module accessed by the other modules instead of defaults everywhere
Do cli header arg parsing in cli module, not api
Merge branch 'develop' into feature/issue-13-make-jspot-usable-programatically

Conflicts:
	lib/extract.js
Merge branch 'feature/issue-13-make-jspot-usable-programatically' into develop