Fix problem with initialization order in `ClassToAPI.scala`.

In `ClassToAPI` both `Private` and `Protected` vals had forward
reference to `Unqualified` so they would get `null` as a result.
Fixed that by rearranging the order of vals being declared.

This fixes a problem described in 9dd5f076ea3d3c1cca257a548646c4807e58879a.
Revert "Revert "Fix sbt/sbt#676: swapped declarations and members in `ClassToAPI`.""

This reverts commit 9dd5f076ea3d3c1cca257a548646c4807e58879a which was a revert
itself so we are back to the state before those two reverts.

The problem that caused revert that happened in 9dd5f076ea3d3c1cca257a548646c4807e58879a
has been fixed in 88061dd26225f611e4be2028ee4b145fbb18bdba.