Removed OpenAL and GLFW3 dependencies on building.
Reviewed platforms and flags

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!

- Renamed VERSION to RAYLIB_VERSION
- Renamed API_VERSION to RAYLIB_API_VERSION
- Renamed RAYLIB_RELEASE to RAYLIB_RELEASE_PATH
- Support Web Assembly compilation on PLATFORM_WEB

OpenAL Soft backend is still available in audio module, I'm thinking if
exposing it for building in some way or just left it there for advance
users to switch to it manually in case of necessity...

It seems there are some platform-dependant issues

- Removed useless templates
- Reviewed all Makefiles
- Rework some code for Android support
- Added resources to advance template

Notice that requries libraries are directly taken from
raylib/release/libs/android folder and nativeLoader.java is generated by
Makefile on the go

Using shared libraries just don't work...

OpenAL Soft and raylib compiled for release and stripped

...almost there! raylib already works, issues with OpenAL Soft
linkage...

- Renamed some folders
- Added some files for testing
- Removed useless files

For some reason it's not working properly... :(

Updated to latest version, not tested

..to avoid blending issues with white background

Removed glew from basic_game makefile as glew is not part of the raylib package (no glew in mingw).