Implement a rudimentary if/elif/else/endif interpretor and use
conditionals in dat/cmdhelp to describe what command each keystroke
currently invokes, so that there isn't a lot of "(debug mode only)"
and "(if number_pad is off)" cluttering the feedback that the user
sees. (The conditionals add quite a bit of clutter to the raw data
but users don't see that. number_pad produces a lot of conditional
commands: basic letters vs digits, 'g' vs 'G' for '5', phone
keypad vs normal layout of digits, and QWERTZ keyboard swap between
y/Y/^Y/M-y/M-Y/M-^Y and z/Z/^Z/M-z/M-Z/M-^Z.)
The interpretor understands
'&#' for comment,
'&? option' for 'if' (also '&? !option'
or '&? option=value[,value2,...]'
or '&? !option=value[,value2,...]'),
'&: option' for 'elif' (with argument variations same as 'if';
any number of instances for each 'if'),
'&:' for 'else' (also '&: #comment';
0 or 1 instance for a given 'if'), and
'&.' for 'endif' (also '&. #comment'; required for each 'if').
The option handling is a bit of a mess, with no generality for
which options to deal with and only a comma separated list of
integer values for the '=value' part. number_pad is the only
supported option that has a value; the few others (wizard/debug,
rest_on_space, #if SHELL, #if SUSPEND) are booleans.
ca22b3fe46