problems with file independence

[masinter]

I think this is a general problem that will interfere with the maintainability of the software. Raised by PR #276

In this particular case, CHAT(SHELL) uses a general function GETHOSTINFO, which was in the file LEAF (which was otherwise unneeded). But GETHOSTINFO does need macros and records from a TCP low-level file moved to "obsolete" in the dropbox days.

one priority should be to discover "called but not defined' or "used free but never bound or set (special/global)