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.