dsp.c: Fix delay calculation when input and output samplerates are different.
dsp.c: Simplify default progress display, add verbose display option.

Verbose mode shows all the information that was shown before. Latency is now
shown as 'input+output' instead of just the total.

In normal mode, the clip and peak indicators will be shown if clip_count > 0.
dsp.c: Show peak level in clip warning.