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 to latest emrun. Update test for that. Fixes #2742.
Changes to embind and interacting with text. Fixed up last commit which deleted some .txt file accidentally.
Integrated final review feedback from ChrisM to ready-for-review topics. Removed the review markup
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
[tracing] Initial tracing API.

This is used in conjunction with a collection & analysis server
to analyze memory usage and other aspects of a program running
under emscripten.
[tracing] Integrate the tracing stuff.
[tracing] Instrument dlmalloc.c

These changes compile out entirely if tracing is not enabled.