Recursively parameterized types can cause stack overflows when
recursively descending type hierarchies if not handled carefully.

In this case we continue the recursive descent using the raw type,
removing the risk of infinite recursion.

Closes scijava/scijava#176

Helper method to determine if a bound of another type is in fact
recursive, with its own type parameter equal to the bounded type.

Previously we were recursively checking bounds of type variables even if
those bounds were themselves recursive. This would create duplicate
mappings that worked incidentally because the values were the same
(since recursive) but this behavior broke in the change to recurse to
raw types instead (avoiding infinite recursion errors)