Docking: Saving local _NoResize flag. (#2583)

Added full "Dear ImGui" prefix to the title of "Dear ImGui Demo" and "Dear ImGui Metrics" windows. Shortened amount of nodes in columns>tree demo.

Docking: Saving the NoTabBar, NoWindowMenuButton, NoCloseButton fields of dock node into the .ini file. Added them to the Metrics window. (#2583, #2423, #2109).

Comments, todo entries, moved ImGuiSelectableFlagsPrivate in higher ranges to match others.

ColorEdit: Fixed the color picker popup only displaying inputs as HSV instead of showing multiple options. (#2587, broken in 1.69 by #2384).

Docking: Clarified terminology of docking/tablist/collapse button into Window Menu button matching master. Added private ImGuiDockNodeFlags_NoWindowMenuButton, ImGuiDockNodeFlags_NoCloseButton flags. (#2583, #2109)

Examples: imgui_impl_opengl3: Fix empty printout on shader load. (#2584) ...

Fixed minor bug in CheckShader and CheckProgram

The log_length reported by 
glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length)
will at least return 1, since the string delimiter is also counted.

The old version would always print and empty string to stderr. This is annoying in the emscripten port, since it prints a red error message to the Javascript console. The new version fixes this behavior.

Docking: Honor style.WindowMenuButtonPosition setting in docking node.

Merge branch 'master' into docking ...

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

Style: Added style.WindowMenuButtonPosition (left/right, defaults to ImGuiDir_Left) to move the collapsing/docking button to the other side of the title bar.

Internal: CloseButton takes an upper-left corner + a size to be consistent with similar widgets.

Internals: Extracted some of the tab bar shrinking code into a ShrinkWidths() function so columns/table can use it.

Fixed InputScalar, InputScalarN, SliderScalarN, DragScalarN with non-visible label from inserting style.ItemInnerSpacing.x worth of trailing spacing.

Merge branch 'master' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Internals: Added InnerWorkRect equal to old InnerClipRect, added InnerWorkRectClipped actually clipped.

Version tag is 1.71 WIP oops

Fix OuterRectClipped not being clipped correctly, which resulted in child window outside visible bound to not be marked with SkipItems. Broken in b50c61c. ...

+ Comments on InnerClipRect being misleading. Demo: Tweak to sizing of child window in the Layout->Scrolling section.

Merge branch 'master' into docking ...

# Conflicts:
#	imgui.cpp

ImFontGlyphRangesBuilder: Fixed unnecessarily over-sized buffer, which incidentally was also not fully cleared. Fixed edge case overflow when adding character 0xFFFF. (#2568)

Fixed crash when appending with BeginMainMenuBar() more than once and no other window are showing. (#2567) + comments

BeginPopupContextItem(): Skip processing when SkipItems is set as LastItemId is unreliable and we assert when it is zero. + Minor comments on columns.

Fixed GCC mem-access warnings (#2565) ...

+ using "if defined" more consistently for Clang.

Docking: Fixed temporarily losing Dockspace flag when merging remaining sibling back into a parent node. (#2563, #2109) ...

Would trigger an assert in the Passthru hole path. Broken by fd5859ed.

Docking: Fixed undocking whole node (from collapse/docking menu button) from losing its size/pos. Made collapose/docking menu id easier to compute for testing.

Update changelog, comments, made empty/no-text clipboard return NULL as with other implementation. Minor style tweaks. (#2546) ...

Fixed IMGUI_DISABLE_WIN32_FUNCTIONS not disabling IME code.

Add native mac copy/paste support to match win32 (#2546)

Docking: Fixed incomplete merge of 36e714a leading to undocking. #2109

Fixed ColorEdit breakage introduced by d3a387c (#2557, #1875, #2034)

Fix undefined behavior (#2561)

Merge branch 'master' into docking ...

# Conflicts:
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_win32.cpp
#	imgui.cpp
#	imgui_internal.h