try to spawn fthreads via flx_world
let driver handle thread/stack tracking for world stop gc
Fold library regression tests into tutorial.
Tutorial reorg.
Fix typo.
comma
Fix.
Rework the introductory tutorial tract.
Bump version
Copy css files too.
Basic edit window.

Add ?edit at the end of a C++ or Felix file
and the text comes up in an edit window.
No colour or anything yet. Just a place to start.

Dues to some weirdness Felix *.fdoc source code
is fine but tutorial *.fdoc pages aren't.
Something to do with the crud the webserver itself
addes around tutorial pages (next/prev buttons).
Prototype edit plugin.
Get colour in the edit window.
Fix edit mode.
Need string.h
Small bug
Minimal code mirror in neutral place.
Edit a bit better.
Fixup code mirror a bit more.

Add a save button.
Implement basic "POST" hander in webserver.
Add --static option to flx_build_rtl.

Throw in some more modes for CodeMirror.