other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
trailing junk since the previous rev. That's too strict. Silently
ignore trailing junk as long as it starts with whitespace. That's
somewhat lax, but will do for now. Closes#982018.
double-remainder problem: x-coordinate SHRT_MAX+1 is truncated to 0 by
cast to coord, then converted by xabs(). This is wrong unless WORLD_X
divides SHRT_MAX+1.
(sarg_xy, sarg_getrange, sarg_range): Use them.
(inputxy): No longer used, remove.
(sarg_type): Use NS_UNDEF instead of 0.
(sarg_list): Change confusing loop control. Properly diagnose
overlong lists; used to silently ignore list tail and return MAX+1,
which made a later snxtitem_list() fail.
(atoip): No longer used, remove. Parsing was broken anyway.
(sarg_type, sarg_xy, sarg_area, sarg_range, sarg_list, sarg_getrange):
Use plain char * instead of s_char *.
