Places a comment above key from group_name.
If key is NULL then comment will be written above group_name. If both key and group_name are NULL, then comment will be written above the first group in the file.
Note that this function prepends a '#' comment marker to each line of comment.
a group name, or NULL
a key
a comment
TRUE if the comment was written, FALSE otherwise
GException on failure.
2.6
Places a comment above key from group_name.
If key is NULL then comment will be written above group_name. If both key and group_name are NULL, then comment will be written above the first group in the file.
Note that this function prepends a '#' comment marker to each line of comment.