When you install emsdk out of the box, the directory is no longer `$(EMSDK_PATH)/python/33.7.4_64bit` but rather `$(EMSDK_PATH)/python/3.7.4-pywin32_64bit` noting the `3.7.4-pywin32_64bit` change on the last file.

Thus, without adjusting this in the raylib Makefile it will throw an error:

```
PS C:\raylib\raylib\src> make PLATFORM=PLATFORM_WEB -B                                                                  emcc -c core.c -Wall -D_DEFAULT_SOURCE -Wno-missing-braces -Werror=pointer-arith -fno-strict-aliasing -std=gnu99 -Os -s USE_GLFW=3 -I. -Iexternal/glfw/include -Iexternal/glfw/deps/mingw -DPLATFORM_WEB -DGRAPHICS_API_OPENGL_ES2              '"python"' is not recognized as an internal or external command,                                                        operable program or batch file.  
```

However, changing this line in the Makefile compiles raylib for web as expected

`"raylib library generated (libraylib.bc)!"`

Co-authored-by: Branlix 3000 <branlix@3000.3k>

- Removed generate_android_toolchain, since version r21 AndroidNDK it's the toolchain
 - Removed external lib native_app_glue, provided by AndroidNDK

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

Corrected issue on web compilation

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

Fix 1102

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

Note that latest emsdk changed paths

Added in a check for x86 and x86_64 branches of android

Added in $(OS) checks to see if we're running on windows or *nix

Added a default location for android ndks and sdks at /usr/lib/android

* 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...

With v2.5.0 out, increment API_VERSION, so binaries dynamically linked
against the released raylib aren't accidentally paired with a development
or later released raylib that may be incompatible.

From the Clang documentation[1]:
> -x<language>, --language <arg>, --language=<arg>
> Treat subsequent input files as having type <language>

Follow the advice. Fixes #840.
[1]: https://clang.llvm.org/docs/ClangCommandLineReference.html

This reverts #841 commit 97160fd970.

Some minor tweaks

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)

The idea is supporting additional raygui and physac modules building with raylib but those modules are distributed as header-only libraries and it makes a bit dificult to build them inside raylib...

Renamed flags for convenience.

Planning to promote raudio module as a simple and easy-to-use front-end for the amazing mini_al library, so the name change.

Name comes from raylib-audio but in spanish it also remembers to word "raudo", meaning  "very fast", an analogy that fits perfectly to the usefulness and performance of the library!

Consequently, raylib version has been bumped to 2.4-dev.