Deprecateds1: stringstring to compare with s2
Deprecateds2: stringstring to compare with s1
0 if the strings match, a negative value if s1 < s2, or a positive value if s1 > s2
since 2.2: See GLib.strncasecmp for a discussion of why this function is deprecated and how to replace it.
A case-insensitive string comparison, corresponding to the standard
strcasecmp()function on platforms which support it.