Inner types in MultiBrush segment definitions can usually be derived
automatically from the start and end types. This is especially
important for segments with different starts and ends, where the Inner
type could be either one (e.g. beach to watercliff changers). Inner
types are now only needed in two cases:
- The Inner type doesn't match either the start or end. For example,
road diagonals.
- The Inner type should only match one of the start or the end. For
example, cliffs which end into clear tiles.
This commit cleans up the unneeded or unwanted Inner type definitions
in the base mods.
c3b22c9102