[AE] Added AC3 Core passthrough for E-AC3 tracks that support it

Added the ability to passthrough AC3 for E-AC3 tracks that have an AC3 core stream.  This only affects devices that can not passthrough E-AC3 (SPDIF, some TV's, etc).  

In addition I also added the ability to have a dependent stream with an E-AC3 core.  Currently the only dependent streams that are supported are with an AC3 core main stream.  This now allows for a dependent stream with an E-AC3 core main stream.  I however have not tested this thoroughly as I have not found a sample that actually contains this.  Any 7.1 non AC3 core samples out there?  This could still be improved as I believe the spec allows for up to 8 dependent streams and currently there is only support for 1 (have seen no samples with more than 1).

This change also affects the number of channels reported for E-AC3 streams.  Currently E-AC3 plus streams are hard coded to 7.1.  I now use the main stream as the number of channels and then modify the number of channels once a dependent stream is found.  This delayed update however does not seem to affect what is displayed.

Open to suggestions or opinions for improvements.  I am not a huge fan of the DVDPlayer change but could not see another way to handle this.
no handling of this case?
anyway, codec changes are handled by DVDPlayerAudio, not here
note that m_dvdPlayerAudio.OpenStream does not drop packets already queued in case of a codec change.