i195: option to interpolate bounds

Added option "interpolate_spatial_bounds" to OcgOperations. For
row and column dimensions, the center coordinates will be used to
interpolate lower and upper bounds. The exterior bounds are also
extrapolated to ensure spatial coverage is not lost.
Merge branch 'master' into i95-interpolate-bounds
removed ocgis/work.py
i206: find origin of odd error messages in verbose output

Using "ocgis_lh" inside dimension objects when the error is caught
by a calling frame results in empty error messages in the log. The
messages are harmless but confusing.