Use make variables $@ and $^ where appropriate.

Ensure `make clean` is idempotent. ...

Prior to this, `make clean` would fail if the project was not already
fully built, and a second invokation would always fail.

Nav: Added links to PNG/PSD files for PS4 and Switch. Fixed suggested Joy-con mapping as per typical Nintendo-style mapping. (#787)

Internal: Moved IM_NEWLINE helper to imgui_internal.h

Added ImGuiConfigFlags_IsSRGB, ImGuiConfigFlags_IsTouchScreen (strictly for user storage)

Renamed ImGuiNavFlags io.NavFlags to ImGuiConfigFlags io.ConfigFlags. (#787)

Renamed ImGuiNavFlags io.NavFlags to ImGuiConfigFlags io.ConfigFlags. (#787)

Renamed ImGuiNavFlags io.NavFlags to ImGuiConfigFlags io.ConfigFlags. (#787)

Examples: DX10: Multi viewport/platform support (based on DX11 version). (#1542)

Examples: NULL pointers for consistency.

Examples: DX12: Empty skeleton toward implementing the multi-viewport api for DirectX12. (WIP/test API) (#1542, #301)

Examples: SDL: Initial attempt at implementing the viewport/platform api. (WIP/test API) (#1542) ...

ImGui_ImplSDL2_Init() now takes a SDL GL context.

Examples: GLFW + OpenGL3: Initial attempt at implementing the viewport/platform api. (WIP/test API) (#1542)

Examples: DX11 + Win32: Initial attempt at implementing the viewport/platform api. (WIP/test API) (#1542)

Viewport: Initial viewport branch+ platform api commit (squashed from previous commits, still very WIP) (#1542)

Metrics: Added option to show begin order, useful for debugging.

Internal: Minor renaming.

Internals: Moving window: test mouse validity while translating window + using SetWindowPos().

Removed DisplayVisibleMin/DisplayVisibleMax facility (as part of # 1542). Misc comments.

Clearing next window data at the end of Begin() more reliably. Misc comments.

Internals: Settings: Added ReadCloseFn to allow handlers to sanitize data on a per-entry basis.

Examples: Misc tweaks/fixes.

Merge branch 'master' into examples_refactor ...

# Conflicts:
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

README.md typo fix

ImRect: Removed misleading IsFinite() function used by some Nav code.

Compacted some old Breaking Changes notes (Pre July 2015 stuff)

Changelog: Added all change infos since 1.53 up to the current version.

Changelog: Added Changelog with info from 1.48 to 1.53. Haven't added 1.53..current yet.

TreeNode: Renamed Beta ImGuiTreeNodeFlags_NavCloseFromChild to ImGuiTreeNodeFlags_NavLeftJumpsBackHere. (#1079)

ImDrawList: Better looking non-AA rectangle (lower-right corner and rounding). (#1646)