Currently, if:
* GCC doesn't supports -no-pie: Build error
* GCC supports -no-pie
    * GCC is not configured with --enable-default-pie: No-op
    * GCC is configured with --enable-default-pie:
            Slightly worse performance because we still generate -fpie code
            (-pie affects linker, -fpie affects compiler)

So instead of probing for existence of -fno-pie -no-pie, remove it altogether.

Fixes #540: Build breakage on Debian 8 with gcc 4.9.

- Preparing MP3 files support
- Jumped version to raylib 2.0-dev (too many breaking changes...)

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!

Supported UTF8 range equivalent to [128..255] (80h..FFh)
Exposed and renamed text function GetGlyphIndex()
Renamed spriteFont parameter name to simply font
Small security check on transmission mission ending screen

Support string replacing to generate newspaper headline
ISSUE: UTF8 characters not supported when drawing to Image

Game developed in the GGJ18, it has some bugs and ending screen is
incomplete... I'll try to keep working a bit more on it.