More scope-walking work. Messing about with Property syntax. I hadn't noticed how hopelessly out of date the SYNTAX.TXT documentation was, it'll have to be totally rewritten before release. Whilst `:.property` is logical for current syntax (`:` is shorthand for the current `PROC`/`TABLE`), there isn't an equivalent if we want to make self-references in a Type-definition, for example (`#.property`?)

I also reworked some of the Master System memory map in 'system.sms.oz80' to reflect intended spacing Property functionality)