w/ Changelog tweaks.

See "window_size_min" test. Waiting for a fuller simplification of this, probably for a future version.

Not guaranting behavior: clamping makes output lossy, size_1+size_2 in theory may be instable but couldn't repro.
API probably needs rework anyhow (should redistribute from provided available space).

BeginChild: undo child name simplification as it reveal an issue with handling of ### in child names.

When the later is fixed we can re-enable this. Essentially reverts 8ee85137.

e.g. for #6579

Broken by 2569c647

Removed 'bool border' legacy versions of BeginChild() as they seemingly have no value other than confusing user and IDE.

Amend 7713c292 (was for #1666, #1496, #1395, #1710)

Amend for 6e7b43b6,79a9e2fd

Backends: Vulkan: (Breaking) full font upload is performed by ImGui_ImplVulkan_CreateFontsTexture(), no need for user code to create or provide a command-buffer. Removed ImGui_ImplVulkan_DestroyFontUploadObjects(). (#6943, #6715, #6327, #3743, #4618)

See changes in example_glfw_vulkan/main.cpp and example_sdl2_vulkan/main.cpp for reference.

Backends: Vulkan: Added ImGui_ImplVulkan_DestroyFontsTexture(), made ImGui_ImplVulkan_CreateFontsTexture() destroy previous one. (#6943, #6715, #6327, #3743, #4618)

Defining IMGUI_DISABLE_OBSOLETE_FUNCTIONS now automaticaly define IMGUI_DISABLE_OBSOLETE_KEYIO. (#4921)

Removed IM_OFFSETOF() macro in favor of using offsetof() available in C++11. Kept redirection define. (#4537)

Backends: OpenGL3: Update GL3W based imgui_impl_opengl3_loader.h to load "libGL.so" instead of "libGL.so.1". (#6983)

Followup to fea52e29

Tables: added flags to TableDrawContextMenu() in order to display selected sections + added internal table->DisableDefaultContextMenu = true way to submit your own contents.

Amend 088ddef9

BeginChild(): added ImGuiChildFlags_AutoResizeX, ImGuiChildFlags_AutoResizeY, ImGuiChildFlags_AlwaysAutoResize + support for SetNextWindowSizeConstraints(). (#1666, #1395, #1496, #1710) + Demo

Note that child don't report ideal content size to parent so nesting may be difficult.
Note 4e4042bc simplified SkipItems logic.
Note e2035a51 standardizing WindowMinSize application on child

Better documented the difference between BeginListBox() and BeginChild() w/ ImGuiChildFlags_FrameStyle.

BeginListBox() can't yet expose child flags because coarse clipping require query of stored size (same issue as with adding resize support to Tables).

BeginChild(): resizing is only clamped on axis where there's no scrollbar. Added an extra ResizeX in Demo->Simple Layout.

BeginChild(): Added ImGuiChildFlags_FrameStyle as a replacement for BeginChildFrame(). (#1666, #1496, #1395, #1710, #462, #503, #263)

Effectively allows us to avoid extending BeginChildFrame() api to mimic BeginChild() new parameters.

Amend 4448d975. Note that functions entry points will eventually be merged into one, so this is not a problem.

Note that the g.NavMoveKeyMods -> g.NavJustMovedToKeyMods chain is not used in this branch. Multi-select uses it.

Made ImDrawCallback_ResetRenderState special value -8 instead of -1 so it is pointer aligned (#6969)

note https://github.com/dearimgui/dear_bindings/issues/56 may not be of direct use as-i.

(Will cherry-pick this from docking to master)

# Conflicts:
#	imgui.cpp

Offset values for ImGuiWindowFlags_NoNavInputs, ImGuiWindowFlags_NoNavFocus, ImGuiWindowFlags_UnsavedDocument.

(ABI breaking but we technically never supported ABI backward/forward compat, thought it is possible that some generated backends be affected)

(e.g. resizing a child window triggering parent scroll) to avoid resizing feedback loop.

BeginChild: Added ImGuiChildFlags_AlwaysUseWindowPadding, obsoleted ImGuiWindowFlags_AlwaysUseWindowPadding. (#462, (toward #1666, #1496, #1395, #1710)

(bonus: will also eventually free a window flag)

BeginChild: Upgraded 'bool border = true' parameter to use a ImGuiChildFlags type and the ImGuiChildFlags_Border value. (toward #1666, #1496, #1395, #1710)

ColorPicker4(): Fixed ImGuiColorEditFlags_NoTooltip when ImGuiColorEditFlags_NoSidePreview is also set. (#6957)

BeginChild(): Internal name used by child windows now omits the hash/id if the child window is submitted in root of id stack of parent window.

# Conflicts:
#	docs/CHANGELOG.txt
#	imgui.h

Windows: tidying up skipitems logic at end of Begin(), normally should be no meaningful side-effect.