Merge branch 'master' into docking

# Conflicts:
#	backends/imgui_impl_glfw.cpp
#	imgui.cpp

examples/example_glfw_opengl3/main.cpp

@@ -96,6 +96,9 @@ int main(int, char**)
 
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOpenGL(window, true);
+#ifdef __EMSCRIPTEN__
+    ImGui_ImplGlfw_InstallEmscriptenCanvasResizeCallback("#canvas");
+#endif
     ImGui_ImplOpenGL3_Init(glsl_version);
 
     // Load Fonts