TEST(BK) UTS:  test that indexing with floats rounds as expected
FIX UTS:  index for time (dimindex) rounding
ENH Sensor proj:  keep top-most points separate
STY:  setup.py
ENH fmtxt:  ADD content arg to Section.add_figure()
FIX plot:  fall back to MPL if no WX App is running
DOC UTS._cluster_bounds():  better error message for empty clusters