pyicont_tb.py: Added some basic xarray features to time_averaging. Removed dtype=IcD.dtype from some functions which do not know IcD.

pyicon/pyicon_tb.py and pyicon/quickplots/pyicon_quickplots.py: Bug fix in calculation time_bnds where mm=1 and we need to go to month mm=12 and yy+=-1.

pyicon_tb.py: Add verbosity to load_hsnap and allow for shifting the data if there is iw specified in case of lon>180.

pyicon/pyicon_tb.py: Added option of using a mask to only interpolate a selected domain in apply_ckdtree.

pyicon/pyicon_tb.py: Bug fixes related to loading amoc data and hfl data when looped over all time indices.

pyicon/pyicon_tb.py: Fixed bug in level interpolation (calc_vertical_interp_weights and zonal_average_atmosphere). New function nctime_to_datetime64 to calculate numpy.datetime64 objects from netcdf time.

pyicon/pyicon_tb.py: Changed radius_of_influence and convert np.nan in apply_ckdtree to masked values everytime (this was prob a bug before).

  * a bit of rearanging routines to get a more logical order
  * new intermediate function: ckdtree_points to calculate grid points
  * new function: calc_north_pole_interp_grid_points for a more
    appropriate grid for polar projections
  * new functions: spherical_to_cartesian and cartesian_to_spherical
  * splitting: mask_big_triangles

  * time_average: Added option to give list of indices over which should
    be averaged.
  * identify_grid: Added atmosphere r2b4 grid.

pyicon.quickplots: Adapted to new arrange_axes and adapted to splitting and moving of quickplot related functions to quickplot module.

Moving pyicon_quickplots and pyicon_view to their specific directories. Adding imports in __init__ files. Moving qp specific functions from pyicon_tb to pyicon_quickplots.py

pyicon_tb.py: Removed calc_bstr and IconVariable which was moved to pyicon_calc and pyicon_IconData.

  * exclude aplly_ckdtree_base from apply ckdtree
  * new: interp_to_rectgrid
  * calc_moc and zonal_average_3d_data: new basin: indopacso
  * new: nctime2numpy
  * get_timesteps: go through every file and concatenate time steps
    instead of allocating array first and assume same number of tsteps
    in each file
  * 1st version of edges2cell
  IconData:
    * new options: omit_last_file, time_mode
    * fpath_tgrid=='auto': take grid file from pool directory
    * if search_str=="": no search is done
    * new: reduce_tsteps
    * more variables loaded from fx file
  * shade: new option draw edges
           cbticks can be array of colorbar ticks

  * identify_grid: Added atmosphere r2b9 grid: r2b9a: icon_grid_0015_R02B09_G
  * IconData.load_vgrid: added more vert. grid variables
  * IconData.load_tgrid: added cell area