Commands arent executed multiple times any longer

Improved Sphinx recognition so that commands are not executed multiple times any longer: Since hyp is updated continuously in the output container
(even if there has been no new "word" recognized) the hypotheses is only checked against
a keyword (i.e. "left") when hyp is concatenated with a recognized command. Only this new added command is then checked to trigger an event. At the moment only panning is implemented. Zooming does not work yet.