[cvs-nhc98] patch applied (hat): Add virtual stack trace on errors + split io.c into parts.

[Malcolm Wallace]

Thu Jan 18 05:33:14 PST 2001  malcolm
  * Add virtual stack trace on errors + split io.c into parts.
    * io.c now becomes browsercomms.c, ident.c, and trust.c
    * added a virtual stack trace when program terminates uncleanly
      (e.g. error, interrupt, blackhole).

    M ./src/old/runtime/Makefile -6 +16
    A ./src/old/runtime/browsercomms.c
    A ./src/old/runtime/ident.c
    A ./src/old/runtime/ident.h
    M ./src/old/runtime/io.c -1724 +14
    A ./src/old/runtime/stacktrace.c
    A ./src/old/runtime/trust.c
    A ./src/old/runtime/ui.h