New functions:
xt_get_primary_group_name()
xt_ff_dsv_() functions auto-generated from xt_dsv_()
API changes:
xt_strviscpy(): Show spaces and newlines normally rather than octal
Improvements to test suite
xt_str2u64() -> xt_str2u64_hash()
xt_ff_read_line_malloc() -> xt_ff_gets_malloc()
Fixes:
#define strlcpy(d,s,l) xt_strlcpy(d,s,l) for Linux GCC 13
(Argument checks fail when defined as strcpy() without length)
Likewise for strlcat()
xt_ff_close() Fix accidental recursion
xt_ff_popen(): Exit child if exec fails