Use logarithmic scale for audio equalizer effect

Currently in the video sequence editor, the audio equalizer effect seems to use a linear scale to display adjustments. I end up fighting the UI because most of the meaningful adjustments happen below 5K Hz.

These are both examples of 30 Hz to 20000 Hz equalizers. Blender's (on the left) uses a linear scale while the one on the right uses a logarithmic scale and leaves much more room for meaningful adjustments.