this was a bug, merge into master ASAP
refresh
switch to a more composable group semantice
simplifed quantile with new grouping semantics, but reopens #2
cbind skips NULLs , repeated fields
not sure why this got more involved than needed
make group keys available
got the group value in without the row dupes
more R-ish name
little optimization for ungroup
no profiling data in git plz
better support for combiners