* json: Allow null for /Header/StrictBody.
* log: Show full ex in ErrorTab when logLevelThreshold <= 2.

* FIX WorkingDir handling when empty.
* prefs: Minor UI fixes, read defaults from schema.
* prefsUI: Show msgBoxes on errors.

* Always write to file-log (even when sent to msg-box).
* file_v3: Completely hide close() method, leave Dispose() available only.

* json: Read defaults from schemas.
* prefs:  Make all props non-required.

* json: more rework parent-sublass behavior.
* FIX /Header/StrictBody to work, add global prefs:/Body/StrictBodies.
* Add /Header/BodySchema and global prefs:/Body/IncludeSchemas for documenting files.
* prefsUI: drop up-to-date check before saving.
* prefsUI: Add Reload button.
* Start using .net Settings, now for window-location.

* gui: rename F_Info --> F_About

* Simplify path-settings of configs.

COMPLETE Switch Config-setings to JSON, separate config/ folder (recreated on startup) from Declaration/ one

* Store WorkingDir as relative to App's Path.
* Selected Editor done via System.Diagnostics.Process.Start and  editor.exe instead of Shell and Path for notepad.exe.
* Minor GUI-work (set icons to dialogs)

CSE status: after Final report, before end delivery