* Made modifications for the utterances to stop immediately when re-calculations happen.
* Made modifications so that voice instructions are now distance array based.
* when in feet, it will be spoken in feet in nearest hundred.
* taking care of alphanumeric characters

* changed DESTINATION_ARRIVAL_THRESHOLD to 15 meters
* Made modifications to improve the re-calculation so that "re-calculation is spoken only once"
* implemented the destination, so that re-calculation does not happen after the destination is reached.
* current position will not change in the mapview if the current location changes and so the location:didupdate method is unchanged. It is assumed that the user is going to search for places when he is static.
* the "current" though is made functional, in this case, the map will be update even if the car is moving.