Fixed a bug with OAuth2.

The OAuth2 redirect URI did not contain the necessary parameters.
Fixed a bug where a redirect was not happening.

The users were not properly being redirected after then authorized the shim to read from an external data source. This should be fixed by returning a 302 and having the redirect URL set as the Location header.

Closes #10
Updated the authorization flow.

There were some issues with how redirect URLs were being built and the external authorization flow as well. This has been updated to make it easier for implementors to create their own ExternalAuthorizationInformation objects. The OAuth v1 implementation has been updated as well.

References #8
Updated how the configuration file was imported.

Before we were storing the custom configuration options in our own Properties object. This is slightly burdensome to external parties and a little confusing. To get around this, we now update the System Properties. This means that command line properties, default propteries, and custom properties are all imported, in that order.
Add the fitbit api jar.
Add the beginnings of a Fitbit shim.
Hardcode some data to be returned from the shim.
Add in the Fitbit API and enough shim code to fetch a single steps
datapoint.
Add in a missing dep for fitbit4j.
Fix up the access token secret stuff.
Clean up the steps fetching code and get ready for adding more data
types.
Expose some more data fields for activity.
Add some sleep data.
Fix up everything for the latest upstream changes.
Fix the returned schema IDs to have the prefix attached.
Add the most of a withings shim that can fetch 4 different data types.
Add rest of withings measure types and schemas.
Refactored schema fetching.
Don't need that empty constructor...
Add a doc comment for getSchema.