Implemented local variable editing. Operands that have a local
variable reference, or are eligible to have one, can now be edited
directly from the instruction operand edit dialog.
Also, updated the code list double-click handler so that, if you
double-click on the opcode of an instruction that uses a local
variable reference, the selection and view will jump to the place
where that variable was defined.
Also, tweaked the way the References window refers to references
to an address that didn't use a symbol at that address. Updated
the explanation in the manual, which was a bit confusing.
Also, fixed some odds and ends in the manual.
Also, fixed a nasty infinite recursion bug (issue #47).
Correctly handle pre-existing underscores and avoidance of
"reserved" labels.
Also, add more underscores to 2012-label-localizer to exercise
the code.
(issue #16)
Most tests pass, but 2007-labels-and-symbols fails because the
expressions recognized by 64tass don't match up with either of the
other assemblers.
This is currently using a workaround for the local label syntax.
64tass uses '_' as the prefix, which is unfortunate since SourceGen
explicitly allowed underscores in labels. (So does 64tass for that
matter, but it treats labels specially when the '_' comes first.)
We will need to rename any non-local user labels that start with '_'.
(issue #16)
