Configsuite

Feature:
- Support context validation for containers

Improvement:
- Allow for chaining BooleanResults, and hence transformations and validators.

- Improve information in setup.py

Bug fix:
- Extractors are now passed to new suite when pushing layers.

Feature:
- Initial documentation written and hosted at read the docs.

Other:
- Minor code improvements.

Features:
- Support for context validation
- Support for layer transformations, transformations and context transformations

Others:
- Remove layer validation
- Accept unicode strings as strings
- No sorting of dict keys

Bug: Fix various errors regarding imports

- New basic types `Date` and `DateType`
- Add six to Python 2 dependencies
- Fix docs import in configsuite's init-file