MANTA-127 Generalize ReadGroupStatsSet for RGs
MANTA-127 re-arrange insert stats to enable RGs
MANTA-127 more refactor to allow stats per RG
MANTA-127 more RG stats refactoring
MANTA-127 fix read group error labeling
MANTA-127 estimate stats per RG
MANTA-127 fix RG logic/runtime based on initial testing
MANTA-127 reduce RG syscalls
MANTA-127 prep for full RG support
MANTA-127 prep deactivated branch merge
MANTA-127 merge details