This reverts commit 2528854664.

* Update compilation warning flags

Removed the -Wall flag that allow many warnings and added manually all the warning flags that don't generate warnings in the src/external folder.
Specifically, these are some of the flags reporting errors in src/external:

-Wmissing-prototypes
-Wunused-variable
-Wunused-value
-Wunused-parameter
-Wunused-function

* Uptade compilation flags in examples with missing -std=c99

Co-authored-by: codifies <nospam@antispam.com>

Note that emscripten upstream branch implements the new asyncify implementation, expected to be faster than emterpreter one.

Now examples can be compiled by module, that's useful when compilation fails at some point

Actually OpenAL is not used any more, it should be using CoreAudio

Contributed simple shader example

I'm not sure why the clean command is so complex (especially given that find -type f -executable | xargs rm -fv works!)
but I fixed the version as is, to support x-pie-executable which was preventing it deleting anything on my system...

- Updated Makefile with new examples

* added multi channel sound replay to raudio
added -fPIC to Makefile for Linux
added simple lighting and audio multi channel to examples Makefile

* not properly reporting audio buffer pool size...

a minor issue: where the location of the file "raylib.rc.data" is wrong, and this will cause an error in compilation.

Contributed by ProfJski

Note that building examples for web as they are (no code adaptation for web avoiding while loop) implies using the emterpreter... and that's very slow!

Found some issues when building for web using latest emscripten 1.38.30, traced the error and found that eglGetProcAdress does not return function pointers for VAO functionality, supported by extension.

It requires more investigation but now it works (avoiding VAO usage)

Solves audio cracking issues

raylib resource data file for Windows platform (containing raylib icon and metadata for executable file) has been renamed to a more consistent name: raylib.rc.data

Also required to work with tcc compiler.

Examples can be compiled for web with no code change at all! Usually
examples need to be refactored for web... using emscripten code
interpreter (emterpreter), it can manage synchronous while() loops
internally... as a downside, execution is very slow...