X.L.StateFull's `FocusTracking` and the eponymous `TrackFloating` were
redundant, hence the former was slated for deprecation. However,
the latter and its host module are somewhat poorly named; the layout
modifier has little relation to floats. As such, it's renamed and
rehosted, becoming the eponymous `FocusTracking`.
The redundant offerings in the original modules are redefined in terms
of the new module where possible, and deprecated.
See: #418; comments on #253, #783.
