Provider Builder for file-based configuration [incomplete]

Hi - I've got the coding itch today :)

Attached is an attempt at a simple method to take a PHP array in the format you mentioned in issue #4 and apply that configuration to an existing Provider using the appropriate methods on the given Provider object.

The idea being that there would be other classes that use this to generate a Provider for you.

A YAML parser then, for example, would be a simple class that takes a filename, parses the YAML file into a PHP array, then uses this class to build the Provider.

Not sure if this is what you were thinking of, but as I said, I had the itch to do some programming!