Very helpful...

Only match when full names match.

This was only necessary in the time where input was upcased right after
reading.

They serve no purpose and make the code less flexible.

Will be much much easier to tests new core routines without having to
re-create their context first.

Also, extract parse.asm from core.asm

When B>1, fsNext failed because HL was changed in the Seek call.

On build, pack `parts/z80` into a CFS and embed it into the emulated
zasm executable as an fsdev. This will allow for the upcoming include
directive to have something to go to.

For now, this is useless except for inflating the emulated zasm's size.

This 'apps' folder is going to disappear. Everything is going to be a
"part" to be assembled through recipes. 'apps' has no meaning.

Instead of buffering input in memory one line at a time, we go in "just
in time" mode and always read contents directly from I/O, without
buffering.

It forces us to implement a `ioPutback` scheme, but on the other hand it
greatly simplifies cases where multiple tokens are on the same line
(when a label is directly followed by an instruction).

The end result feels much more solid and less hackish.

We'll need it for an upcoming "local labels" registry.

Will need it soon.

It was previously skipped on a local label.

That is, labels with code following right afterwards.

With local labels, these two will have to be decoupled.

Facilitates debugging

Gives clearer output on errors. Easier debugging...

`xor c` didn't do what I thought it did at the time. Newbie mistake,
there are probably a lot like this scattered around...

Also, add warning on attempts to write to ROM.