Get Mpress more reliably in the Updater

Parameter errors to stdout/err if in /Silent mode

Rationalise detection of major version

Fix 'Base Exe\Path' not expanding built-in variables

Fix compile of new .exe failed in 1.1.37.01a.

Local help now shows v2 if Base compiler directive present

Add sub-version check for base file *.exe allowed

Set edition date

Added /ScriptGuard2pss parameter

'Permit /script switch'

Allow 64-bit interpreter use on 64-bit Windows