Update parse-options API to catch mistakes to pass address of an
integral variable of a wrong type/size.
* ps/parse-options-integers:
parse-options: detect mismatches in integer signedness
parse-options: introduce precision handling for `OPTION_UNSIGNED`
parse-options: introduce precision handling for `OPTION_INTEGER`
parse-options: rename `OPT_MAGNITUDE()` to `OPT_UNSIGNED()`
parse-options: support unit factors in `OPT_INTEGER()`
global: use designated initializers for options
parse: fix off-by-one for minimum signed values
2bc5414c41