Returns the value associated with key under group_name as an
integer.
If key cannot be found then 0 is returned and error is set to
G_KEY_FILE_ERROR_KEY_NOT_FOUND Likewise, if the value associated
with key cannot be interpreted as an integer, or is out of range
for a gint, then 0 is returned
and error is set to G_KEY_FILE_ERROR_INVALID_VALUE
Returns the value associated with key under group_name as an integer.
If key cannot be found then 0 is returned and error is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND Likewise, if the value associated with key cannot be interpreted as an integer, or is out of range for a gint, then 0 is returned and error is set to G_KEY_FILE_ERROR_INVALID_VALUE