Release 0.9.15 "Myriam" - GitHub automation, portability

This release focused on GitHub and GitLab automation

New features
============

* GitHub automation automatically builds various packages
* Preparation for GitLab automation (still largely untested)
* Windows simulator
* Android package
* WebAssembly application (WASM) now has help and configuration files
* DM42n build (differs from DM32 only in the help files)
* Dockerfile to create a container with the simulator
* Add `ρ` in `RangesMenu`
* Accept units when creating a range from components
* Add `Range→` command that expands ranges with units

Bug fixes
=========

* Corrected typos in some builtin constants
* Spelling and grammar fixes in documentation
* Build failure for wasm due to use of `source`, a `bash`-only syntax
* WebAssembly application no longer uses 100% CPU
* The simulator can now be launched from any directory
* The macOS simulator correctly launches from the Finder or Dock
* Portability bug fixes in the DMCP emulation
* The Settings menu is now correctly refreshed after `ResetModes`
* Fix double-shifted arrow keys
* Correctly show help for `Swap`, `Negate`, and `Cycle`
* Fix order on stack for `Explode` on a range value
* Android build bug fixes

Enhancements
============

* Add osx program in lauch.json
* The simulator no longer overwrites configuration files by default
* Builds that use `gcc` now enable more warnings
* Simplify shift-handling logic

Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>