- keys compared lexicographically using String::compareTo
- Range metadata additionally written into parquet file footers
- Trim fat & few optimizations to speed up indexing
- Add param to control whether input shall be cached, to speed up lookup
- Add param to turn on/off range pruning
- Auto compute of parallelism now simply factors in amount of comparisons done
- More accurate parallelism computation when range pruning is on
- tests added & hardened, docs updated
