INIT ndvar: copy form eelbrain
ndvar: remove data-object references
ADD: UTS dimension
FIX: dimensions.UTS

base on tmin, tstep, nsteps
FIX: NdVar

- __repr__, indexing: only use name if not None
- subdata(): index dim with index (not arg)
- RM "properties" kwarg
ENH: NdVar.__repr__

use dimensons' dimrepr
cleanup
ENH: NdVar.get_data()

Allow accessig single dimension data with a string
ADD: ndvar.from_stc() and .resample()
ADD: ndvar stc example
ADD example: load_stc
DOC: ndvar