To straighten out includes and to pave the way into zasm being part of
the same "include CFS" as parts, we make zasm includes namespaced.

This shrinks the CFS size to 21k from nearly 64K. This will allow me to
kick the can down the road a bit with regards to supporting storage
seek/tell greater than 64K.

I'll get to it, but first, I want to assemble zasm with zasm!

Simplifies comment stripping through sed.

Also, increase scratchpad size. It wasn't big enough for some
expressions in shell unit.

Couldn't get rid of instrUpcode though, too complicated.

We don't treat "," exactly as a whitespace anymore. We have specific
processing for it.

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.