Define .precision to more canned parse-options type to avoid bugs
coming from using a variable with a wrong type to capture the
parsed values.
* rs/parse-options-precision:
parse-options: add precision handling for OPTION_COUNTUP
parse-options: add precision handling for OPTION_BITOP
parse-options: add precision handling for OPTION_NEGBIT
parse-options: add precision handling for OPTION_BIT
parse-options: add precision handling for OPTION_SET_INT
parse-options: add precision handling for PARSE_OPT_CMDMODE
parse-options: require PARSE_OPT_NOARG for OPTION_BITOP