Updated change log

Author: jim-easterbrook

CHANGELOG.txt

@@ -15,6 +15,11 @@ GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+Changes in 1.5.1:
+  1/ Added gp_camera_get_single_config(), gp_camera_set_single_config() and
+     gp_camera_list_config() functions, if used with libgphoto2 v2.5.10+.
+  2/ Changed version related compilation flags.
+
 Changes in 1.5.0:
   1/ API change! The gp_file_open function now allocates and returns a new
      CameraFile object.