v0.4.4

A minor release with enhancements.

This version introduces a new class called Matchpoint which will allow automated matchups between netCDF files and point observations in pandas dataframes. This class is created using nc.open_matchpoint. Matchups are generated by using the add_data, add_points, add_depths, and matchup methods.

For datasets, ds now provides a more informative summary of dataset contents.

The split method now automatically sorts the files, so that they are sorted by date when temporal splitting occurs.

The methods surface, merge_time and tvariance``` have been removed after periods of deprecation. Use top, mergeandtvar`` instead.