Fix some potential undefined or implementation-specified behavior and simplify code at the same time :)
simplify select_overload
more template simplification
Remove scons-tools for now since it doesn't work outside of IMVU.
Check if context creation was successful before accessing it
Update preamble.js
Merge pull request #2744 from hamishwillee/incoming

Integrate fixes to FAQ from Chris.
Update AUTHORS
add j0 etc. functions to musl; 1.23.2
Merge pull request #2745 from Daft-Freak/patch-3

Check if context creation was successful before accessing it
Merge branch 'patch-1' of https://github.com/H2CO3/emscripten into incoming

Conflicts:
	AUTHORS
Merge pull request #2743 from waywardmonkeys/remove-scons

Remove scons support for now since it doesn't work outside of IMVU.
Merge pull request #2741 from waywardmonkeys/update-embind-again

Update embind again
clarify SIMD option
Update indexes (and associated changes) for most of remaining sections
Remove temporary scratchpad files
move Debugging topic up level (no longer in index)