*
@method removeAt(<start>, [end])
@returns Array
@short Removes element at <start>. If [end] is specified, removes the range between <start> and [end]. This method will change the array! If you don't intend the array to be changed use %clone% first.
@example

['a','b','c'].removeAt(0) -> ['b','c']
[1,2,3,4].removeAt(1, 3)  -> [1]

*
function(start, end) {
      var i, len;
      if(isUndefined(start)) return this;
      if(isUndefined(end)) end = start;
      for(i = 0, len = end - start; i <= len; i++) {
        this.splice(start, 1);
      }
      return this;
    }