Cope with test names containing angle brackets
Verify the number of steps vs. expected number of cursor positions
Fix doc length check when iterating backwards
Report one test per cursor position document fragment
Print function result rather than function.toString for test description
fixup! Cope with test names containing angle brackets
Add test showing position stability issue near annotations
Add additional tests showing position stability problems
Fix position instability around highlighted annotations

By checking only nodes that pass the supplied node filter, the position
logic can safely ignore out-of-place cursors near highlighted annotations.