The instruction operand editor and data operand editor are very
different, but there's no need to impose that distinction on the
user. They want to edit the operand either way. We now provide a
single "edit operand" menu item, and open the appropriate dialog
based on what they have selected.
This uses Ctrl+O as the keyboard shortcut, stealing it from
File > Open.
(issue #11)
If set, the first word of the file is used to set the load address.
The initial code entry hint is placed at offset +000002 instead of
the start of the file.
Set it to true for the C64 system definition.
(issue #23)
