Merge branch 'master' into docking

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

examples/imgui_impl_metal.h

@@ -11,6 +11,8 @@
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
 // https://github.com/ocornut/imgui
 
+#include "imgui.h"      // IMGUI_IMPL_API
+
 @class MTLRenderPassDescriptor;
 @protocol MTLDevice, MTLCommandBuffer, MTLRenderCommandEncoder;