24bit per sample is not supported internally and automatically converted 16bit

Not required anymore

* Chromium needs a larger audio buffer: https://github.com/dr-soft/miniaudio/issues/150

* changed PLATFORM_WEB to __EMSCRIPTEN__

Some internal defines have been exposed in config.h

It could be useful in a future...

Switched custom WAV laoding/saving funtionality to drwav library, it also provides the required mechanisms to stream wav data.

All functions requiring sizeof() now follow the same convention:

NUM_ELEMENTS*NUM_SUBELEMENTS*sizeof()

Current looping system was broken, `loopCount` has been converted to `bool looping` and user can enable/disable with `music.looping = false`. `SetMusicLoopCount()` has been removed.

Most warning were related to types conversion (casting required) and unsigned/signed types comparisons.

Added preprocessor directives (_CRT_SECURE_NO_DEPRECATE; _CRT_NONSTDC_NO_DEPRECATE) to avoid warnings about unsafe functions, those functions are safe while used properly and recommended alternatives are MS only.

Some external libraries still generate warnings.

There are multiple #define values around raylib, usually not exposed for redefinition, just reviewed all of them to allow users redefining them on compile time if required.

Also, multiple #define have been renamed and commented.

* added log warning for unsupported file extension for music stream

* updated error log message for music stream when file format isn't supported

Errores fixes:
models.c,2843 Either the condition 'fileData!=NULL' is redundant or there is possible null pointer dereference: fileData.
raudio.c,805, 806, 807, 808, %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.

NOTE: Two libraries still use custom allocators: glfw and stb_vorbis

Use new file I/O ABI

There could be some cases where we need to define the internal audio buffer size, now it's possible.

RENAMED: InitAudioBuffer() to LoadAudioBuffer()
RENAMED: CloseAudioBuffer() to UnloadAudioBuffer()

Renamed some defines and reviewed some comments.

Just for clarification, no plans to remove libc dependency, just did some code analysis to see how much raylib depend on stardard C library. My conclusions:

 - stdlib.h: primary dependency is for malloc() and free()
 - stdio.h: primary dependency is for FILE access, maybe it could go through a custom ABI?
 - string.h: just around 8 functions required
 - math.h: just around 8 functions required
 - others: 1-2 functions required for some other headers

* Update to miniaudio 0.10

This replaces the old ma_pcm_converter with ma_data_converter.

At this time of this commit, miniaudio 0.10 is still in the testing
phase. To make it easier to update miniaudio.h during this period, I've
temporarily moved the @raysan5 Win32 customizations to raudio.c because
there may be quite a few updates to miniaudio.h during this time.

* Use miniaudio's built-in volume control.

Added SUPPORT_TRACELOG_DEBUG config

* [core] REDESIGNED: Implement global context

* [rlgl] REDESIGNED: Implement global context

* Reviewed globals for Android

* Review Android globals usage

* Update Android globals

* Bump raylib version to 3.0 !!!

* [raudio] REDESIGNED: Implement global context

* [raudio] Reorder functions

* [core] Tweaks on descriptions

* Issues with SUPPORT_MOUSE_GESTURES

* [camera] Use global context

* REDESIGN: Move shapes drawing texture/rec to RLGL context

* Review some issues on standalone mode

* Update to use global context

* [GAME] Upload RE-PAIR game from GGJ2020 -WIP-

* Update game: RE-PAIR

* [utils] TRACELOG macros proposal

* Update config.h

Short non-looping sounds can sometimes think they need to keep playing and will output their first few frames again. This helps to break out of all the loops instead of just this one.

* explained a bit more the core_window_letterbox example

* fixed a few 'ups' moments that could lead to mild head pain and time loss