view icons/README @ 1315:ed3009a50f81 piper

Make SVDEBUG always write to a log file -- formerly this was disabled in NDEBUG builds. I think there's little use to that, it just means that we keep adding more cerr debug output because we aren't getting the log we need. And SVDEBUG logging is not usually used in tight loops, I don't think the performance overhead is too serious.

Also update the About box.

Icons are from various GPL'd sources, including the GIMP image editor,
KDE crystalsvg icon set, Rosegarden audio and MIDI sequencer, and Hydrogen
drum machine.  Some modifications and new drawings by Chris Cannam.