All "stop pings" are now explicitly made at appropriate places. This
fixes a problem I've introduced in the last commit where RAM+ was
unexpectedly part of a stable ABI because of "HERE" usage in dummy.fs.
This system will, anyways, soon change because boot.bin and z80c.bin
will be built during the same process (but there's a bit of retooling
to do before I get there).
Virgil Dupras