code: function deltaEncodeIntegers( array, numType ) {
  	var delta = new NUMTYPE_CLASS[numType]( array.length - 1 ), l = array[0];
  	for (var i=1; i<array.length; ++i) {
  		var v = array[i]; delta[i-1] = v - l; l = v;
  	}
  	return delta;
  }
docs: Encode an integer array with delta encoding
  
  @param {array} - Source Array
  @param {Class} - The class of the underlaying numeric array (ex. Uint8Array)
  
  @return {array} - An array with the initial value and the delta-encoded payload