Changed ContentType and rate

Changed ContentType and rate to support all cameras.
Merge pull request #23 from LingoLasse/axistransmit

AxisTransmitAudio: Changed ContentType and rate
Removed duplicate semicolon
Added audioTransmit

Added start and stop functions for audioTransmit to the api
audioTransmit

Changed name of audioTransmit functions for consitency and moved the so
that they are in the same order as in the js api
Save url

Implemented property to save the url which is needed to manage muting
and unmuting of the microphone.
Microphone mute and unmute

Added functions to stop and start playing after muting and unmuting
microphone and changing the microphone volume.
Added audioTransmit functions

Added functions for starting and stopping microphone input transmission
to camera speaker.
Unmute fixed

unmuteMicrophone now returns if the gain value is not 0.
Added type to startAudioTransmit

Added a type parameter to the startAudioTransmit function that defaults
to axis.
Changed volume values

Both microphone and speaker volume now are in the range from 0-100 in
the api.
Fixed startAudioTransmit default type value
Moved microphone functions

Moved microphone functions for mute, unmute and volume to AxisTransmit
class. Now saving the microphone instance which prevents stopping of the
stream when properties are changed.