control signal filter errors

[Oeyvind]

Some analysis signals (k-rate) in the analyzer are filtered with tonek. It seems the filter is tripped when the input is -INF, and never recovers, leaving the analysis feature clamped to zero or below. Workaround is to limit filter input throughout where there is a tonek. Do also check tonek failure with Csound list, should it tolerate -INF?