Use summary towers whose file backing is real32-sized

Add close function now that we can have file backing

Use file backing

Provide seekDistanceHint

Comment

Add backing arg now required by summary tower

Further range checks

Use un-padded summary towers (so we can see when the waveform starts and ends)

Bail out as soon as the budget is exceeded

Further fixes for start area - avoid crash due to trying to handle negative-length ranges

Handle start/end of waveform sensibly in interpolating mode

Update for change to api

Debug output

Backed out changeset 0f40d0967116

Try circles with halos. Doesn't look good

The squares are a little jarring actually

Fix test

Add a little more debug

Use dpi; some experiments with circular points

Harmonise COPYING files