RAYMATH_EXTERN_INLINE was renamed to RAYMATH_HEADER_ONLY, which user code
may define if they want to use it as header-only library. If multiple
files in the same project define RAYMATH_HEADER_ONLY, they might each
have duplicate out-of-line definitions of the same functions.

By default, raymath.h exposes inline definitions, which instructs the
compiler _not_ to generate out-of-line definitons, if out-of-line
definitions are required, those of the file defined with
RAYLIB_IMPLEMENTATION are used instead. There may be only one such file.

In C++ mode, the compiler will select only one out-of-line definition
automatically, so no need to define a RAYLIB_IMPLEMENTATION.

Unfortunately, we have to remove raymath function declaration from
raylib.h as those declarations would lead to duplicate out-of-line
definitions which would yield linker errors. This problem didn't
exist with GNU89 or C++, because there multiple defintions are ok,
but in C99 they aren't.

This reverts commit 6ffc8cb799.
and commit e4d7bbec1e.
which I pushed by mistake...

RAYMATH_EXTERN_INLINE was renamed to RAYMATH_HEADER_ONLY, which user code
may define if they want to use it as header-only library. If multiple
files in the same project define RAYMATH_HEADER_ONLY, they might each
have duplicate out-of-line definitions of the same functions.

By default, raymath.h exposes inline definitions, which instructs the
compiler _not_ to generate out-of-line definitons, if out-of-line
definitions are required, those of the file defined with
RAYLIB_IMPLEMENTATION are used instead. There may be only one such file.

In C++ mode, the compiler will select only one out-of-line definition
automatically, so no need to define a RAYLIB_IMPLEMENTATION.

Unfortunately, we have to remove raymath function declaration from
raylib.h as those declarations would lead to duplicate out-of-line
definitions which would yield linker errors. This problem didn't
exist with GNU89 or C++, because there multiple defintions are ok,
but in C99 they aren't.

Rename: GetHexValue() renamed to ColorToInt()
Added: ColorToHSV()

Otherwise we may run into LoadDefaultFont and crash in rlLoadTexture
Also moves InitTimer() before InitGraphicsDevice(), to allow it to be
tested even if InitWindow ultimately fails.

Otherwise we run into an assertion failure inside GLFW's glfwGetVideoMode.
Example:
http://www.cpantesters.org/cpan/report/b4ba5894-0bdb-11e8-841e-2c60b04e1d2d

This is related to #456.

Note that this version is under development and could be buggy on some
platforms...

In case graphic device could not be created it returns false instead of
failing with an error tracelog (and consequently closing the program).
Window initialization success could be checked with new function
IsWindowReady()

You can't do much with raylib if glfwInit or glfwCreateWindow fails,
currently it just exits by means of TraceLog(LOG_ERROR.
User code, however, might want to fall back to a text-only UI
or display a warning if raylib can't be used.

glfwSetWindowPos was called on a NULL window, triggering an assert
inside GLFW. Check for failure and exit cleanly by means of
TraceLog(LOG_ERROR instead.

Just in case ClearBackground() is not used after BeginTextureMode(), it clears fbo to color defined by previous ClearBackground()

If not using busy wait loop, linkage with WINMM in Windows platform is
required

Issues when dealing with FBOs

Review comments

Trace log messages could be configured with this function to select wich
ones are shown

Monotonic time since InitWindow() could be retrieved with this function.

Reviewing GetTime() functionality

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...

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.

Feature macros need to be defined before #including any headers,
preferably through the build system, but this is good enough.

Fixes a compile error on my fork's Travis CI.

Now header is truly multiplatform...

Actually still a small pending check on XBOX gamepad controls that
hopefully will be removed with next GLFW 3.3

Support Universal Windows Platform (UWP):
- Windows 10 App
- Windows Phone
- Xbox One

Corrected issue with RPI_CROSS_COMPILE

SetWindowTitle()
GetExtension()

Now it works great with reviewed maths

Some other tweaks...

Now it should be coherent with OpenGL math standards

Exposed some raymath useful functions to raylib API

Consistent with similar functions in raymath