Pygeode

- Cartopy (version > 0.17.0) is now supported in addition to Basemap for map
projections.
- Error reporting for openmulti() has been improved.
- Non-ASCII character support in NetCDF attributes are now better handled.
- Improvements and bugfixes in stats module
- Fixed crash in eof module.
- Changed default netcdf opener to use standard netcdf4 python package.

- Fix bug where pygeode.formats.netcdf4 fails if the libnetcdf shared library
is not installed on the system. It should not be required, since the
interface uses the Python netCDF4 package to handle I/O.
- Updated the INSTALL file with more up-to-date information.
- Removed warning message when libnetcdf unavailable. This was always
displayed, even when libnetcdf was not actually needed. This could cause
confusion if using the newer pygeode.formats.netcdf4 interface, since it
doesn't require the shared library at all.

- Support for Python 3.
- Fix ext_xarray.from_xarray() method, which was failing on xarray versions
> 0.10.0.
- Handle Var objects passed into netcdf.save and netcdf4.save.
- Properly detect attributes that are 1-element list of strings when writing
to netcdf.
- Force attributes from netcdf4 module to be string instead of unicode.
- Support for netcdf4 groups.
- Fix lazy variable loading for netcdf4 module.
- Added new bar() and errorbar() plot wrappers.
- Fix colorbar=False option for showvar.
- Fix nl=0 option for clfdict.
- Updated progress bar to be compatible with progressbar2 package.
- New rotatelon() and clip() functions.

- Handle netCDF time units that are separated by a "T" instead of a space.
E.g., "hours since 2010-02-01T03:00:00".

- Fix bug in plot_v1, where the 'projection' entry was removed from the
projection dictionary supplied by the user. This was causing problems
when creating sequential plots, where only the first one had the right
projection.
- Fix bug in hdf4 interface. Files that had dimensions with no associated
coordinate variable were crashing with a KeyError.

- Added nan-aware versions of climatological mean operations.
- Added standard deviation and nan-aware standard deviation classes for all
time subdivisions of climatological operations.
- Added count operations in climat module that return number of non-NaN
elements.
- Climatology operators can now be invoked as methods of Var objects.
- Add a "netcdf4" format for interfacing with the netCDF4 python module.
- Add support for entry points for pygeode.plugins and pygeode.formats.
- Add entry points for custom axes.
- Added pcolor operation to AxesWrapper.
- Better support for dimensionless Var objects (issue 108).
- Fix stack overflow when dealing with large 1D arrays (issue 107).
- New module pygeode.ext_xarray for converting to/from xarray objects.
- New hasaxis() and getaxis() methods for Dataset objects.
- Var.get() now returns a writeable copy the array.