I'm reserving the 100-200 range for non-bootstrapping needs.

This allows us to write LATEST at proper offset in emul/stage1.fs in
cases where we set a nonzero BIN(.

I have a working offset-by-0x100 stage0 now.

With cross compiling and IMMEDIATE words, things get icky with stable
ABI references. For the same reason that EXIT, (br) and (br?) need to
stay at stable offsets, these word references will not have BIN(
properly applied at Inner core xcomp.

The solution for now is to adjust during EXECUTE, which is ugly and
inefficient, but I don't see a better solution right now.

Will be useful as kinds of "#ifdef"s during xcomp.

ref #97

fixes #97

Will be useful for assembling binaries for the TRS-80 which can't start
at addr 0.

And adjust rc2014/eeprom recipe

Big bootstrapping change which greatly reduces the role of the modern
operating system in the bootstrapping process.

It's now a simple flag updated by the C< implementation. No more
routine pointer.

The goal is to avoid tons of "ok" during a LOAD operation.

The SD card driver is a bit too slow to be bearable. I'll write
_crc16 in z80 and see how it goes.

This is done by adding a "C<* override" layer that is reset to 0 on
ABORT.

The problem was that when ABORT happened during a LOAD, we had a
resetted RSP and started from a clean INTERPRET, but LOAD didn't
have the opportunity to restore C<*, which caused it to continue
interpreting from the faulty BLK.

With a C<* override, we don't need to *restore* C<*, we just need to
clear the override.

This is more than cosmetic, it's also highly usable. The presence
or absence of the "ok" message allows us to know whether the command
aborted. Previously, the "> " prompt appeared when the system expected
a prompt in the INTERPRET context, whether the previous command aborted
or not.

Also, this allows us to get rid of that ugly FLAGS global variable.

The way is clear for complete stage1 bootstrapping on the RC2014
target!

We can get rid of acia.z80, but not of acia.fs yet, we still need it.

It doesn't serve much purpose and takes up many precious bytes. And,
after all, parsed didn't do it either...

This allows us to remove forth/z80a.fs. Another big step towards
self-hosting!

I don't remove z80a.fs yet because build process needs it, but that
will change shortly.

It's not possible to reliably determine its end and with some memory
initialization scenarios, it makes RLDICT fail.

As I wrote in my "Clarify signed-ness" commit, "0 <" is broken.

Also, made this unit a bit more compact. The RC2014 stage1 can
really use some breathing room...

Also, fix some PSP leaks related to LOAD.

and remove cfspack, which will not ever be used again.