Merge branch 'master' into docking

# Conflicts:
#	docs/CHANGELOG.txt
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp

examples/imgui_impl_glfw.h

@@ -18,6 +18,7 @@
 // Only override if your GL version doesn't handle this GLSL version. Keep NULL if unsure!
 
 #pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
 
 struct GLFWwindow;
 struct GLFWmonitor;