PATCH: 72 hour countdown

[Colin Campbell]

New today, for 21:00 MDT Monday July 25

   Issue 153: \once \set fails to restore previous setting - Rietveld Issue 4810042: Fix 153: \once\set properly restores the context property
   Issue 620: It should be possible to specify more specific spanner bounds. - Rietveld Issue 4814041: Fix for Issue 620.
   Issue 1678: Midi gives false warnings - Rietveld Issue 4757043: MIDI: reset channel counters when done; issue 1678
   Issue 1433: \breakDynamicSpan breaks with \break ("bounds of spanner are invalid") - Rietveld Issue 4630070: Fix issues 1259 and 1433 (\breakDynamicSpan and a spanner's style=#'none over a line break)
  Issue 1259: DynamicTextSpanner #'style = #'none doesn't work over \break

And a couple of Rietveld-only patches:

  Issue 4754054: Fixes note column skylines by adding a stem tremolo pure height function.
  Issue 4801045: Produces better error messages when programmers forget to document a property.

And finally, my hearfelt thanks to you all: there are no "holdovers" from the last patch batch!
  
cheers,

Colin

-- 
The human race has one really effective weapon, and that is laughter.
-- Mark Twain