Episode VI: Return of the ZeroDBline
Revert "replace "-inf" with UTF8 infinity symbol"

This reverts commit 7f2000ec8b0d6e0d3a6e22db44a8859301d35791.
remove cruft
narrower narrow mixer strips
remove unique track number from meterbridge
Revert "show track-ID in mixer" and "...towards unique track numbers."

This reverts commits:
  ca54ea2b462869bfd9254a493d073ca1e9ad4b8e.
  9e87e058e26b87013e89ddf5d3b7358d50024d60.
limit meterbridge window height to multiples of 16px

(workaround to bad resizing performance, realloc drawing areas)