add MakeOneElemSlice, for golang/go#76135

improve WaitGroup.Go/GoN. See golang/go#76126

remove ScaleDuration. Add Scale/Scale2 instead

add ScaleDuration, for golang/go#75265

modify TrackError so that TrackError(&err, err) returns true

modify TrackError to TrackError(err, ptrToZeroSizeError) panic

if errors.Is(err, ptrToZeroSizeError) return true for err == ptrToZeroSizeError.

modify TrackErrorOf so that it doesn't distinguish value error type and pointer error type.

Add TrackError, for golang/go#74488.

TrackError(anIncomparbleErr, anIncomparbleErr) panics.

Add TrackErrorOf, for golang/go#51945.

BoolKeyMap and BoolElementMap now only support the builtin bool type.

remove the _slice type and move its methods to ttop functions.