Added missing AnswerCall function / Removed un-needed call to ConnectAudioLinkToDevice(true)

Spokes Wrapper C#:

* Version 1.0.24b:
* Date: 19th Sept 2013
* Compatible/tested with Spokes SDK version(s): 2.8.24304.0
* Changed by: Lewis Collins
*   Changes:
*     - Added missing AnswerCall function to allow softphone to let
Spokes know
*       when user answered incoming call using softphone GUI.

Spokes EZ Demo:

* Version 1.1.0.5:
* Date: 18th Sept 2013
* Changed by: Lewis Collins
*   Changes:
*     - Removed un-needed call to ConnectAudioLinkToDevice(true) when
call has been
*       answered, and ConnectAudioLinkToDevice(false) when call has
ended.
*       (For IncomingCall/OutGoingCall/AnswerCall functions, Spokes
already does this
*        for you)