Examples: SDL: Fix for Emscripten/Android/iOS on Docking branch.

Merge branch 'master' into docking ...

# Conflicts:
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp
#	imgui.h

Examples: Made imgui_impl_win32 drag gdi32.lib for GetDeviceCaps(). (#2327)

Examples: OpenGL3: Using GLSL 4.10 shaders for any GLSL version over 410 (e.g. 430, 450). (#2329) [@BrutPitt]

Viewport: Added ImGuiViewportFlags_NoFocusOnClick + support in imgui_impl_win32. Made windows with no decoration always set the _NoFocus flags. (#1542, #2117) ...

Fix e.g. clicking on protruding combo box stealing highlight from parent window with decoration.

Merge branch 'master' into docking ...

# Conflicts:
#	imgui.cpp

Examples: DirectX9: Fix Clang warning.

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/README.txt
#	imgui.cpp

Removed trailing spaces from text files. (#2038, #2299)

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt
#	imgui.cpp
#	imgui_draw.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/example_sdl_vulkan/main.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_sdl.cpp
#	examples/imgui_impl_vulkan.h
#	imgui.cpp

Examples: OpenGL2: Added (yet another) comment/instruction against using opengl2 with modern OpenGL. (#2297)

Removed trailing spaces (#2038, #2299)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_win32.cpp

Examples: Win32: Using wc.lpszClassName instead of duplicating the literal. + tweak README format.

Examples: Win32: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages. (#2264)

Examples: Win32: Fix for older Windows SDK.

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt

Merge branch 'master' into viewport ...

# Conflicts:
#	docs/CHANGELOG.txt
#	examples/imgui_impl_win32.cpp
#	imgui_demo.cpp

Examples: Win32: Using IsChild() to be compatible with windows created within a parent. (#1951, #2087, #2156, #2232)

Examples: DirectX9: Explicitly disable fog (D3DRS_FOGENABLE) before drawing in case user state has it set. (#2288, #2290)

Examples: DirectX12: Targeting 10.0.14393.0 instead of 10.0.16299.0 (available on AppVeyor, and higher version doesn't seem necessary).

Merge branch 'viewport' into docking

Merge branch 'master' into viewport ...

# Conflicts:
#	docs/CHANGELOG.txt
#	examples/imgui_impl_win32.cpp
#	examples/imgui_impl_win32.h

Examples: Win32: Added support for XInput games (if ImGuiConfigFlags_NavEnableGamepad is enabled).

Examples: Win32: Using GetForegroundWindow() instead of GetActiveWindow() to be compatible with windows created in a different thread. (#1951, #2087, #2156, #2232) [many people]

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui_internal.h
#	imgui_widgets.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui.h
#	imgui_internal.h

Examples: Allegro 5: Properly destroy all globals on shutdown. (#2262)