Docking: Made DockBuilderSplitNode/DockNodeTreeSplit work even if the node doesn't have a size yet. (#2357, #2109) ...

Followup to fa0ce4b7d, at that time I came to the conclusion that programmatic split couldn't work without knowing the size ahead of it. I forgot the reason for that.  May bite us back!

Docking: Fixed assert in DockContextProcessDock() preventing some uses of DockNodeBuilder api. (#2357, #2109)

Merge branch 'master' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui.h

Selectable: Tweaks for #2347 (demo, changelog, member position)

Selectable: add support for specifying text alignment on selectables (#2347) ...

Adds a style variable to Selectable that allows clients to specify the
text alignment within Selectables, adds a section in the demo to
demonstrate selectable text alignment, and a pair of sliders in the
style editor to change selectable alignment on the fly.

In terms of implementation, this one is extremely simple: Selectable was
already calling an API that supports text alignment, but had hard-coded
it to top-left. This changes that to just pass the style variable
straight through to RenderTextClipped. Backwards-compatibility is
preserved by defaulting the text_align parameter to (0, 0), i.e.,
top-left.

This also fixes a bug with selectable text rendering that caused
right-aligned text in a selectable to be clipped incorrectly, because
the wrong clipping rectangle was being used.

Made it illegal/assert when io.DisplayTime == 0.0f (with an exception for the first frame). ...

Causing too many subtle side-effect, e.g. IsNavInputPressed() would return true multiple times in a row.

Demo: Added Auto-Scroll option in Log/Console. Comments. Removed some ImColor() uses.

Font: Moved functions to internal block (not enforced). Made ConfigData pointer const. Added link to stb's notes.

Font: Fixed high-level ImGui::CalcTextSize() used by most widgets from erroneously subtracting 1.0f*scale to calculated text width. Among noticeable side-effects, it would make sequences of repeated Text/SameLine calls not align the same as a single call, and create mismatch between high-level size calculation and those performed with the lower-level ImDrawList api. (#792)

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.

Window: Fixed initial width of collapsed windows not taking account of contents width (broken in 1.67). (#2336, #176)

Merge branch 'master' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui_demo.cpp

Minor tweaks to reduce false positive of PVS Studio static analyzer.

Menus: Tweaked horizontal overlap between parent and child menu (to help convey relative depth) from using style.ItemSpacing.x to style.ItemInnerSpacing.x, the later being expected to be smaller. (#1086)

Added IsItemActivated() as an extension to the IsItemDeactivated/IsItemDeactivatedAfterEdit functions which are useful to implement variety of undo patterns. (#820, #956, #1875)

Internals: EndGroup: Removed unnecesary parameter to ItemSize()

Internals: Removed unnecessary code.

Merge branch 'master' into docking ...

# Conflicts:
#	imgui_internal.h
#	imgui_widgets.cpp

Fonts: Fixed crash if FontGlobalScale is zero. Correctly debug naming default font if not 13 px. Demo: Moved PopupRounding along with other rounding values. Metrics: Displaying indexes with idx to be correct / less misleading.

Docking: Fixed less of node size/pos caused by 1f2bdd37 (#2109)

Docking: Fixed dragging docked window with _NoMove flag (#2325)

Merge branch 'master' into docking ...

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

Internals: Exposed internal SetWindowPos to imgui_internal.h (for imgui-test)

Revert part of change from 5536eded. Fixed drag and drop in docking branch. (#2331, reopening #2325)

Removed io.DisplayVisibleMin/DisplayVisibleMax (which were marked obsolete and removed from viewport/docking branch already).

Removed io.DisplayVisibleMin/DisplayVisibleMax (which were marked obsolete and removed from viewport/docking branch already).

Merge branch 'master' into docking (enable range_select merge) ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Internals: Tracking dummy select scope id (currently always zero) to facilitate merging of the range_select branch. (#1861)

Internals: Track ActiveIdHasBeenPressed (similar to ActiveIdHasBeenEdited). This is currently mostly for the benefit of the range_select branch. (#1861)