Rename config-build.xml to build.config, move it to the root directory,
and add MSBuild flags for SDL, FFmpeg (unused yet) and OpenGL.

All these changes will allow us to more easily add Lol Engine as a
submodule of another Git project.

There might be issues with lolremez but at first sight it seems to work.

Since C++11 threads are available on every platform that has threads, we
no longer need our pthread implementation. The LOL_FEATURE_CXX11_THREADS
macro is gone, too, and we now just use LOL_FEATURE_THREADS.

Note that it is still necessary to link with -lpthread or -pthread on
some platforms, so we don’t throw that part away.

MeshViewer first pass

a bug that causes the log files to be saved to an incorrect location.

to external so as to avoid some autocompletion collisions with "configure".

LOL_RELEASE are set by msbuild, and use the debug PSGL on the PS3.

we want Xinput but not D3D (ie. OpenGL).

and MinGW-built, because of some weird %rip corruption at runtime when
linking the MSVC DLL with mingw-w64.

and add a new "UseBullet" configuration flag.

Added lol::phys::Simulation, lol::phys::EasyPhysics for easy physic uses.
Added PhysicsObject, wich hold EasyMesh & EasyPhysics components so it is easy to use. Easy seems to be the consensus.
BtPhysTest now works with new physics classes.

Known problem for this commit:
Physics is not properly setup.
There might be memory leaks, I don't think I've parsed all new/delete.
A LOT of primitives are not taken into account.

library (the same that we use for the engine), and link with winmm.lib and
dxguid.lib on that platform.