Decide on location of player API and document it

[Danielku15]

Description

The player interaction is currently split into 2 areas: Directly on the API object, and on the Player subproperty. The public interface for player interaction must be unified and documented.

Possible Solutions

Either the low level alphaSynth player is not exposed and the main API provides properties/methods for it. Or the alphaSynth API becomes the main API and the methods on the main api object are removed.

[Danielku15]

Player API was introduced on main API facade.