By setting a new optional parameter, `errorBoundsStdDev`, to the number
of standard deviations to use when computing error bounds, the return
type for both the SketchMergeAggregator and the SketchEstimate
PostAggregator can be changed from a simple double (estimate) to a JSON
object containing the estimate, expected high bound, expected low bound,
and standard devations used when computing bounds (same value as passed
in).
add unit tests for IndexMergerV9 and fix some bugs
add more unit tests and fix bugs
handle null values and add more tests
minor changes & use LoggingProgressIndicator in IndexGeneratorReducer
make some static class public from IndexMerger
minor changes and add some comments
changes for comments
Will Lauer
Himanshu Gupta
Kurt Young