Undocumented return values for CVodeB and IDASolveB

[dweindl]

The sundials 7.1.1 documentation suggests that the only non-negative return value from CVodeB is CV_SUCCESS. However, it may also return CV_TSTOP_RETURN. (Unrelated: the last sentence in the Notes section of CVodeB is duplicated just below.)

The same applies to IDASolveB and IDA_TSTOP_RETURN.

I don't know whether *_TSTOP_RETURN should be added to the documentation, or whether these function should not return that at all. (Those return values can be observed, for example, in the cvsRoberts_ASAi_klu and idasRoberts_ASAi_klu examples.)