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).

... and switch from debug build to release

I've added .PHONY targets and fixed "clean" recipe.

I've renamed all makefile files to "Makefile" because they appear in the first files.

I've added "-ldl" library, it's necessary to compile the project.

I've cleaned the GNU/Linux compilation, now you can compile without useless parameters.

If you have raylib on standard directories ("/usr/local/include/raylib/raylib.h" for the header and "/usr/local/lib/libraylib.a" for raylib library) you can compile without edit the makefile.

I've changed all default target names with 'all'. Here there is the explanation: <https://www.gnu.org/prep/standards/standards.html#Standard-Targets>.

- Fixed Android locking screen bug. OnDestroy() was called when locking
screen.
- Power button input must be handled by OS.
- AndroidManifest.xml is affected by configChanges="screenSize".
- Updated library header for android template.