jslib: Remove references to seek/rate
Audio: Do not emit audio stopped if denied access.
AudioTransmit: Improved error when connected

If AudioTransmit already is connected, and the user tries to
connect again, it now gives the appropriate error message.
Player: Set initial default configs

Added all available configs in the default config object.
Also set all these when the player starts, so it's really
the default.
README: Updated config defaults