Support Atmos command line

This patch makes cc65-built Atmos files look like BASIC programs (with machine language) instead of pure ML programs.  And, the tape files don't have the autostart flag turned on.  That means:

1. We finally are allowed to type command-line arguments for Atmos programs.
2. We don't need to remember an address number, in order to start an Atmos program; we just type "RUN".
Look at the last hunk in the diff of `libsrc/atmos/crt0.s`.  I needed to add a byte to the end of the program file.  But, I didn't want it to be permanent; I wanted to re-use that location.  I chose the easiest way to do it.