Refactor: Separated sensor management from frame handling

I'm going to integrate gesture recognition as well, which is a different
type of frame management, and it makes no sense to keep sensor management
on both frame handlers.
KinectBody will also include the body tracking id

This makes it easier to refer to the original value, which we will need
when evaluating and tracking gestures.
Refactor: new AKinectEventArgs, BodyFrameReadyEventArgs is now generic

We will need to create other type of Kinect-related event arguments, this
saves us having to duplicate the sensor id validation (as well as any
other base parameters we care to add later).

Changes BodyFrameEventArgs into a generic KinectItemListEventArgs, since
we will use the same class for notifying about lists of gestures.
Renamed BodyFrameReady->FrameReady, only have one type of frame each
Generic versions of KinectBodyBag, Kinect receivers

We'll be sending more data over the network than just bodies, so making
these generics allows us to use a single interface for all lists of
items.
Removed KinectBodyReceiver

I'm not really using it and only keeping the last information received,
so this is the time to decide if I want to integrate it into the other
or not.  It might be worth keeping as an option of KinectBagReceiver for
the gesture data.
Sending gesture data over the wire, added new test console for gestures
Improved code documentation
New user-settable sensor ID
Added reference to the latest public SDK beta
We only support one sensor, updating logs
Clarifying comments
Removing unnecessary parameters
New CustomData dictionary on KinectBody, see comments for details
New KinectVector3 methods for calculating distance, operations
Clarified SittingProcessor uses
Updating readme before releasing v0.3
Merge branch 'release/0.3'