Debug Tools: Added 'io.ConfigDebugIniSettings' option to save .ini data with extra comments.

Moved from compile-time to runtime flag. Applied docking specific change to this cherry-picked commit.

# Conflicts:
#	docs/CHANGELOG.txt

imgui.h

@@ -2048,6 +2048,8 @@ struct ImGuiIO
     // - backends may have other side-effects on focus loss, so this will reduce side-effects but not necessary remove all of them.
     // - consider using e.g. Win32's IsDebuggerPresent() as an additional filter (or see ImOsIsDebuggerPresent() in imgui_test_engine/imgui_te_utils.cpp for a Unix compatible version).
     bool        ConfigDebugIgnoreFocusLoss;     // = false          // Ignore io.AddFocusEvent(false), consequently not calling io.ClearInputKeys() in input processing.
+    // - tools to audit ini data
+    bool        ConfigDebugIniSettings;         // = false          // Save .ini data with extra comments (particularly helpful for Docking, but makes saving slower)
 
     //------------------------------------------------------------------
     // Platform Functions