Basic Flask setup, entity API.
Added metering point API, brought entity API in line with the AMON API documentation.
Created first draft of a schema for sensors.
Updated requirements versions.
Renamed directory that contains code just for the AMON format.
Added boilerplate READMEs
Removed DELETE handler from the API.
Tidied up the AMON database model.
Refactored code to make it more modular:
* Made base URL for the AMON module /amon/
* Moved models.py out of the schema directory
* Created app, db, and api variables at the application level

Added logging support.
Added BadRequest handlers.
Added "status" message to responses.
Improved metadata handling.
merged in bitbucket changes