Merge branch 'master' into docking

Examples: Vulkan: Rewrote scissor processing to match other examples more closely. Removed extraneous +1 of scissor extent height.

Examples: Vulkan: Support draw_data->FramebufferScale correctly matching a79785c for on Metal/GL2/GL3. (#2306, #1676)

Merge branch 'master' into docking ...

# Conflicts:
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp
#	imgui_widgets.cpp

ImDrawData: Added FramebufferScale field (currently a copy of the value from io.DisplayFramebufferScale). ...

This is to allow render functions being written without pulling any data from ImGuiIO, allowing incoming multi-viewport feature to behave on Retina display and with multiple displays. If you are not using a custom binding, please update your render function code ahead of time, and use draw_data->FramebufferScale instead of io.DisplayFramebufferScale. (#2306, #1676)
Examples: Metal, OpenGL2, OpenGL3: Fixed offsetting of clipping rectangle with ImDrawData::DisplayPos != (0,0) when the display frame-buffer scale scale is not (1,1). While this doesn't make a difference when using master branch, this is effectively fixing support for multi-viewport with Mac Retina Displays on those examples. (#2306) Also using ImDrawData::FramebufferScale instead of io.DisplayFramebufferScale.
Examples: Clarified the use the ImDrawData::DisplayPos to offset clipping rectangles.

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

Removed trailing spaces (#2038, #2299)

About, IO: Added io.BackendPlatformName, io.BackendRendererName for informational/QA purpose.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_sdl.cpp
#	examples/imgui_impl_win32.cpp
#	imgui.h

About, IO: Added io.BackendPlatformName, io.BackendRendererName for informational/QA purpose.

Merge branch 'master' into viewport

Examples: Vulkan: Avoid unreferenced parameter warning. (#2162)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx9.cpp
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_vulkan.cpp

Examples: Using "dear imgui" terminology in all examples headers/comments + fix minor typo.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/example_glfw_opengl3/main.cpp
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp
#	imgui_internal.h

Examples: Vulkan: Minor tweaks.

Examples: Vulkan: Viewport: Tweak to improve framerate on multiple-viewport situations, tho it is still halving the unthrottled framerate on nvidia for some reason.. Followup to 4dea032 (#1542)

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui.h

Examples: Vulkan: Fixed handling of VkSurfaceCapabilitiesKHR::maxImageCount = 0 case. Tweaked present mode selections.

Merge branch 'master' into viewport ...

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

Examples: imgui_impl_vulkan: Comments (re)

Examples: imgui_impl_vulkan: Comments

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp

Examples: Cast to ImTextureID instead of void* when assigning to TexId. Applied to all examples. (#2015)

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Examples: Comments, bits of documentation

Fixed merge.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_win32.cpp

Examples: Vulkan: nverted the parameters to ImGui_ImplVulkan_RenderDrawData() to be consistent with other bindings.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx10.h
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_glfw.h
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl2.h
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_sdl.cpp
#	examples/imgui_impl_sdl.h
#	examples/imgui_impl_vulkan.h
#	examples/imgui_impl_win32.cpp