When using FormatText() several times in same function, returned string is static and so, the same is returned, resulting in failures on shader loading.

Contributed by ProfJski

Now shader uses `fragTexCoord` that are the full screen texture coordinates normalized, instead of `gl_fragCoord`, the unnormalized screen coordinates

Also changed path to shader back to what it was originally.

Now dividing by the zoom instead of multiplying (in the shader), so zoom works as expected. Also zoom increase/decrease is now scaled depending on the current zoom.

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!

Redesigns, deletes and renames

Also noted authors propertly on contributed examples

Now it's required on Windows if not using a busy wait loop

Variable operations inside the functions should be evaluated before the function operations.