REAPER v6.43+dev1229

v6.43+dev1229 - December 29 2021

* Includes feature branch: render internals simplification/cleanup
* Includes feature branch: user-defined action overhaul
* Includes feature branch: media item normalization
* Includes feature branch: media explorer toolbar
* Includes feature branch: media item fixed lanes
* Includes feature branch: JSFX internals overhaul/cleanup/modernization
* Includes feature branch: Windows very long pathname support
+ Control surfaces: fix CSURF_EXT_SETSENDVOLUME notifications when in write mode and fader-scaled envelopes
+ JSFX: allow override of refresh rate using options:gfx_hz=60 etc
+ JSFX: fix memory bounds checking on arm [t=261271]
+ Project notes: improve behavior relating to project notes flags and loading projects in REAPER 6.38 and earlier [t=261242]
# macOS: untweak arm64 worker thread synchronization timings