saugns v0.3.7. New channel mixing (panning) syntax. The old P "keyword" for panning has been replaced. Note that more changes remain to be done to remove the old behavior of grouping the parameter setting for all operators on one line. Place each on a new line in the meantime to give it its own value. Syntax changes: * Replace panning 'P' keyword with channel mixing parameter 'c' and 'S c' for default. The scale changes from 0.0-1.0 left-right to (-1.0) left, 0.0 center, 1.0 right. And the letters 'C', 'L', and 'R' become named constants for 0.0, (-1.0), and 1.0. Some additional refactoring is done, for some more lower-hanging fruit in ideas from the 2020-06 "mgensys" redesign version. The commit sequence is expanded a bit further down for further work toward the redesign goals, with notes on remaining bugs.