Some programs like tools could not require audio support

Develop

Build shared libs, games and examples on CI

Now with external OpenAL and GLFW dependencies removed,
we don't have to worry about installing them in CI.
Shared libraries are now always built along with static libs.
Games and examples are built everwhere except for Visual Studio,
because Physac needs pthreads, which VS doesn't provide.

If shader file could not be found on loading it crashed, instead added
fallback to default shader!

Let the user choose if using rres external library

Add library versioning to Make/CMake build systems

Less maintenance overhead that way,
given that make/CMake now also do library versioning.

See #401 for the discussion.
Also bumps version number to 1.9.2 without the -dev,
because neither ELF nor MachO like such a suffix.
The -dev suffix will have to be restricted to the git tags.

Updated to latest GLFW library and working on Wayland support, still
looking how to implement it on raylib because it just exposes
PLATFORM_DESKTOP and defaults to X11 windowing system on Linux...

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...

Added dr_wav for a future use

mini_al integration

Updated raylib version to 1.9-dev for development pourposes.

Next raylib version is planned to implement a big amount of changes, so
the version bump.

Added support compilation with cmake for FreeBSD

Otherwise using a compiler that defaults to -std=c89 or -std=gnu89 will
fail. Example:
http://www.cpantesters.org/cpan/report/abb85066-d283-11e7-9926-b2f4efb9c382

Apparently, -m32 Travis CI build was broken: -m32 was overridden by
-std=gnu99.  This fixes that.

Note that raylib can now be installed via Homebrew

[ci skip]

They were disabled because they failed to build,
but this patch set fixes the build on Linux and macOS.

This doesn't apply to the AppVeyor build on Windows yet;
it currently fails at linking with OpenAL.

Forgot that one the first time round, which created some unnecssary
releases.

... for now.
Syntax was confusing Travis CI, AppVeyor is reporting 401,
so lets see if this change at least fixes Travis.

If this doesn't work, it might be that @raysan5's token is required.