Added null checks and error for microphone
Add possibility to reference DOM element directly on instantiation
Added check for multiple instances of player
Added errors for play/pause etc
No longer set microphone to null on stop

This caused an error when stopping the microphone the second time and thereafter.
Single quotes for state strings

Removed pause event from pause functopn
Merge pull request #70 from LingoLasse/http

HTTPClient: Added errors for play/pause etc for HTTP client
Merge pull request #69 from LingoLasse/mic

AxisTransmit: Added null checks and error for microphone
Merge pull request #67 from LingoLasse/reference

JSLIB: Add possibility to reference DOM element directly on instantiation
Moved errors to ErrorManager
Added option to throw errors