Visual Test Shell for BACnet SVN

Clean up and finish support for max-segments-accepted in Confirmed-Request header:
- keyword MAXSEGS in scripts
- add to Device edit and persisted data

- Ease initial configuration: guide first-timer (or New Workspace) through Device, Port, and Name dialogs.
- Revise some annoying initial values (useless list columns, window positions)
- Add executor to do device discovery using Who-Is and ReadProperty (Tools menu)
- Add executor to read properties and generate the object-list section of an EPICS (Tools menu)

- Add user preference for EPICS editor (default Notepad.exe)
- Save selected EPICS file even if it has errors, else the EDIT button won't work
- Include ALL EPICS-listed properties in read-object scripts (formerly only those with non-? values)

Refactor BackupRestoreExecutor and InconsistentParsExecutor, moving common code to new parent class SendReceiveExecutor.

Device tree: sort object-type and property-ID controls, simplify numeric type and property entry

Changes to read-all-properties
- Set default DA on EPICS and read-all dialog to "IUT" rather than first-in-name-list
- Add option to use ReadPropertyMultiple for read-all

Add Send dialogs for Who-Is-Network-Number and Network-Number-Is
Convert SendVendorNPDU to a more general Send Raw Network Message, standard or vendor proprietary

Feature Request: 1059124: Add max_segments_accepted to send confirmed requests.

Improve entry of proprietary property IDs: show defined, reserved, and proprietary ranges.
Change captions in backup/restore dialog to clarify usage of timeouts.

Extend "any" keyword:
- save or load from variable ot EPICS
- compare