code: function rm(changeList, property, index, count, a) {
          var finalIndex = index ? index - count + 1 : 0
          changeList.push({
              type:'rm',
              path: property,
              index: finalIndex,
              num: count,
              vals: a.slice(finalIndex, finalIndex+count)
          })
      }
docs: adds an 'rm' type to the changeList