CheckCollisionRecs() returns true on edge-collision what means that the
snake eats the fruit when colliding with it but also when sliding by one
unit above or below the fruit.

If the initial fruit position collides with the snake's body a new
position for the fruit is generated but without adding the grid offset.

Inspired by #504.
Instead of requiring the user to do PLATFORM_ANDROID #ifdefery,
have the android_main entry point exported by raylib and call
the user-defined main. This way many games could (in theory)
run unmodified on Android and elsewhere.

This is untested!

Simplified to match raylib installer package folder structure

Those games have been developed by students and ported to a common base
template. Some of them still require some review to be consistent with
each other (formatting, variables naming, code structure...)