Merge branch 'master' into docking

+ fix warning fix for mingw+dx9
# Conflicts:
#	backends/imgui_impl_dx9.cpp
#	imgui.cpp

backends/imgui_impl_dx11.cpp

@@ -311,6 +311,7 @@ static void ImGui_ImplDX11_CreateFontsTexture()
         subResource.SysMemPitch = desc.Width * 4;
         subResource.SysMemSlicePitch = 0;
         g_pd3dDevice->CreateTexture2D(&desc, &subResource, &pTexture);
+        IM_ASSERT(pTexture != NULL);
 
         // Create texture view
         D3D11_SHADER_RESOURCE_VIEW_DESC srvDesc;