This is the flask specific RESTful API layer.

The aim here is to receive and process arbitrary URLs into their consituent elements and
query parameters, which can then be interrogated along with the supplied headers and method
to determine validity of the request and respond accordingly.
Simplified the flask interaction, and started work on the URL validation

The zen_path_info.PathInfo class provides URL decomposition and reassembly.

The decomposed URL is then passed to the validator code which will determine
its validity.

The aim is that zen_api.routing_start() will:
	- Decompose the URL
	- Pass for validation as well formed API call
	- Pass for user authentication
	- Pass for user authorisation
	- Handle the request
Added tests to the validator code, showing progress in validation of URL