move AM constructor exception tests

13-exceptions.t only contains exceptions thrown because of bad AM
constructor input, so move these tests (ignoring redundant ones) into
01-accessors.t, which tests the constructor. Rename 01-accessors.t to
better communicate its function. Organize the other contained tests
into subtests so that the theme of testing the AM constructor is
clearer.
move given data classification tests

The last of the classification tests (for now) seemed to
be in 05-given.t. Move these tests (cleaning up where needed) into
02-classify.t in their own method. Remove extraneous test data. Update
TODO.
general cleanup

Replace all `diag` calls with `note` calls, since we are using
Test::More 0.88 and note is better. Fix test file comments where
problems are found. Fix anyt other random thing found.