* update large example
* pass block down to <Text> for performance, closes#700
* add get-ranges benchmark
* optimize getRanges(), closes#699
* add serialization benchmarks
* optimize Raw.deserializeRanges() by computing marks once, closes#701
* change .merge calls to .set for performance
* change updateDescendant() to use getAncestors() for memoization
* change getPath() to use getAncestors() for memoization
* switch getTexts() and friends to use arrays while iterating
* rename split-block benchmark
* update benchmark compare script