New major release of csound-extended

[gogins]

This will be version 2.0 of csound-extended and will implicitly depend upon updated releases of csound-android, csound-examples, csound-vst3-opcodes, and cmask.

• [x] I am no longer maintaining csound-aeolus due to the advent of Organtec.
• [x] Review and update all README.md, release notes,GitHub pages, and documentation.
• [x] Create a new csound-extended-manual repository to host a GitHub pages live version of the Csound reference manual.
• [x] Ensure all examples run, including online WebAssembly examples and Android examples.
• [x] Verify and document asdf workaround for OpenMusic. Can't get it to work.
• [x] Improve WebAssembly examples for easier startup of Csound. Implement startup and shutdown if possible, otherwise run Csound always but enable turning off all notes and sending new pieces to Csound. Just made async/await consistent.
• [ ] Clean up unit tests for CsoundAC.
• [x] Fresh builds and releases of csound-extended, csound-android, csound-examples, csound-vst3-opodes.

[gogins]

Subsidiary tasks:

• [x] Better-behaved Play and Stop buttons, as per suggestion of Art Hunkins. Implemented using GetScoreTime to detect whether Csound is playing (return value > 0).
• [x] Better handling of async Csound Play buttons. Is now completely synchronous using async/await for all platforms.
• [x] Better formatting of the Csound Reference Manual index-frames.html for different devices.
• [x] Update the builtin player for the manual to use the player.html code.

[gogins]

Fresh builds:

• [x] csound-extended
• [x] csound-examples
• [x] csound-vst3-opodes
• [x] csound-android

[gogins]

New releases:

• [x] csound-extended
• [x] csound-examples
• [x] csound-vst3-opodes
• [x] csound-android

[gogins]

Still need to upload csound-android to Play Store.

[gogins]

Note: App bundle doesn't run, it seems it may not be tracking required plugin opcode .so files.