Merge branch 'master' into docking

# Conflicts:
#	backends/imgui_impl_dx10.cpp
#	backends/imgui_impl_dx10.h
#	backends/imgui_impl_vulkan.h
#	backends/imgui_impl_win32.cpp
#	docs/CHANGELOG.txt
#	examples/README.txt
#	examples/example_glfw_opengl2/main.cpp
#	examples/example_glfw_opengl3/main.cpp
#	examples/example_glfw_vulkan/main.cpp
#	examples/example_sdl_directx11/main.cpp
#	examples/example_sdl_opengl2/main.cpp
#	examples/example_sdl_opengl3/main.cpp
#	examples/example_sdl_vulkan/main.cpp
#	examples/example_win32_directx10/main.cpp
#	examples/example_win32_directx11/main.cpp
#	examples/example_win32_directx12/main.cpp
#	examples/example_win32_directx9/main.cpp
#	imgui.cpp
#	imgui.h
#	imgui_demo.cpp
#	imgui_internal.h

examples/example_sdl_vulkan/main.cpp

@@ -1,11 +1,12 @@
-// dear imgui: standalone example application for SDL2 + Vulkan
-// If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp.
+// Dear ImGui: standalone example application for SDL2 + Vulkan
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
-//   You will use those if you want to use this rendering back-end in your engine/app.
+//   You will use those if you want to use this rendering backend in your engine/app.
 // - Helper ImGui_ImplVulkanH_XXX functions and structures are only used by this example (main.cpp) and by
-//   the back-end itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
+//   the backend itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
 // Read comments in imgui_impl_vulkan.h.
 
 #include "imgui.h"
@@ -385,7 +386,7 @@ int main(int, char**)
         style.Colors[ImGuiCol_WindowBg].w = 1.0f;
     }
 
-    // Setup Platform/Renderer bindings
+    // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForVulkan(window);
     ImGui_ImplVulkan_InitInfo init_info = {};
     init_info.Instance = g_Instance;