Patches/9.15

The patches below can be applied to Modeller 9.15 to fix some minor problems. (Use the Unix `patch` command, or apply them by hand.)

(!) The patches are listed in chronological order (oldest first), so you should apply them in this order to avoid problems.

• loopmodel-special-patches.patch: Fix a bug which, under some circumstances when loopmodel.special_patches() was overridden, would cause coordinates to be incorrectly assigned and/or a "list index out of range" error.