Same thing as in zasm.

Also, make empty strings be parsed as invalid by parseDecimal.

During expression parsing, if a local label was parsed, it would
select the local registry and keep that selection, making
subsequent global labels register in the wrong place.

Starting to feel interactive...

Allows for the ".fill x-$" pattern.

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

They serve no purpose and make the code less flexible.

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

It always reads in the scratchpad with the same max size. No need for
DE-dancing anymore.

It will make tokenization cleaner and it also makes the instruction
table significantly more compact.