Depreciation messages in Chrome

[zz85]

Thanks for this lovely library. Just wanted to report that Chrome has started to warn about some depreciated apis.

[Deprecation] BiquadFilterNode.frequency.value setter smoothing is deprecated and will be removed in M64, around January 2018. Please use setTargetAtTime() instead if smoothing is needed.
[Deprecation] BiquadFilterNode.Q.value setter smoothing is deprecated and will be removed in M64, around January 2018. Please use setTargetAtTime() instead if smoothing is needed. See https://www.chromestatus.com/features/5287995770929152 for more details.
[Deprecation] OscillatorNode.frequency.value setter smoothing is deprecated and will be removed in M64, around January 2018. Please use setTargetAtTime() instead if smoothing is needed. See https://www.chromestatus.com/features/5287995770929152 for more details.

[zz85]

I made an initial patch here zz85/nwc-viewer@73d0248