Multithreading in DGLWindow.cpp

#ifdef _X11_IMPLEMENTATION
if (DGL::getApp()­>getMultiThreaded())
RenderSurface::initThreads();
#endif
#ifndef WIN32
if (!DGL::getApp()­>getMultiThreaded())
m_surface­>useConfigEventThread(false);
#endif

This appears to be related to threading, and what to do if you're running
multi-threaded. I think for now you shouldn't worry about threading, and
just comment it out. We can deal with it later, as Qt does its own
threading. You might want to make single threading the default by changing
DGL.cpp, line 39, from

bool DGL::m_multiThreaded = true;

to

bool DGL::m_multiThreaded = false;

and this way all the multi-threading code will be automatically skipped.