Before you could choose between Merlin-style and generic. Now
there's a combo box that lets you choose Merlin, cc65, or
"common", the latter being used for 64tass.
Gave cc65 its own expression generator, as the precedence table seems
atypical if not unique. Configured 64tass to use the "simple"
expression mode.
Added some operations on a 32-bit constant to 2007-labels-and-symbols
to exercise the current worst-case expression (shift + AND + add).
Tweaked the Merlin expression generator to handle it.
(issue #16)
Changed the "quick config" buttons for the asm config and pseudo-op
tabs into a drop-list and "set" button. The default values for
each assembler are now defined in the Asm*.cs file, rather than in
the settings code.
Rather than have each assembler get its own app config string for
the cross-assembler executable, we now have a collection of per-
assembler config items, of which the executable path name is one
member. The Asm Config tab has an auto-generated pop-up to select
the assembler.
The per-assembler settings block is serialized with the rather
unpleasant JSON-in-JSON approach, but nobody should have to look
at it.
This also adds assembler-specific column widths to the settings
dialog, though they aren't actually used yet.
