Updated some location/area names; collapsed Turnback Cave.

Updated some location/area names; collapsed Turnback Cave.

This had been done before, but some of the changes were lost when I
re-ripped Diamond and Pearl.

Also, Turnback Cave has been collapsed into seven sections rather than
four.  The previous change in particular ignored that the encounter
rates for the first three areas were lower than elsewhere.  I'm
conjecturing wildly, but I believe those first three are the actual
pillar rooms, and the following four identical groups are the groups of
rooms between the pillars.