Now it's blazing fast. It modifies image.data directly.

Previous version could take up to 3-4 seconds to draw a line... now it takes some nanoseconds...

As noted in #539, the symlink check was to support compiling raylib on
VirtualBox vboxfs as no symlinks are supported there.

With me using Linux as daily driver outside VirtualBox now, this 'feature'
is most likely unused by anyone, but still annoys other users (#791).
Just revert it and be done with it. If there are really others building
raylib on vboxfs or a similarly crippled file system under Linux, they
should now step forward when their build breaks.

This reverts commit b8ca51fd01.

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

Actually, project just adds 50MB of ANGLE libraries not related to raylib.
Also reviewed UWP project to consume ANGLE from the NuGet package.

* added log warning for unsupported file extension for music stream

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

- Added NULL return if the replacement string (`by`) is empty
- Reordered sanity checks since there's no need to initialize variables if the strings are invalid.

* Fixed offset check in GenImageFontAtlas

* Fixed code formatting to follow raylib notation rules

It seems there is some related issue on emscripten side... but I'll keep the icons here despite not displayed properly for the moment.

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'.

* [cppcheck] Improvements in SaveStorageValue() in core.c

in file core.c cppcheck shows errors only in function SaveStorageValue():

* Common realloc mistake: 'fileData' nulled but not freed upon failure
* Memory pointed to by 'fileData' is freed twice.

Validation:
* Tested examples/core/core_storage_values.c
* Launched Unit Test for this function
* Rerun CPPCHECK afer fix

* [cppcheck] Change functions header to accept only positive position in files

Changes:
* Functions SaveStorageValue(), LoadStorageValue() (core.c)
* Functions LoadFileData(), SaveFileData() (utils.c)
* Headers in raylib.h

Validation:
* Tested examples/core/core_storage_values.c
* Launched Unit Test for these functions
* Rerun CPPCHECK afer fix

* Update ImageDraw*() functions to match arguments of Draw*()

Updated draw functions:
ImageDrawPixel()
ImageDrawPixelV()
ImageDrawCircle()
ImageDrawCircleV()
ImageDrawLine()
ImageDrawLineV()
ImageDrawRectangle()
ImageDrawRectangleV()
ImageDrawRectangleRec()

* [nodepadpp] Update Notepad++ ImageDraw defintions

This updates the Notepad++ definitions with the updated ImageDraw methods.

* [examples] Add ImageDraw calls to textures_image_drawing

* Update ImageDraw*() methods

This reverts commit 2528854664.