Use strength_scale instead of fixed value for Blue-RedGreen strength
This should especially improve maps for Gaussian patterns, but also direction maps
Merge pull request #563 from Tobias-Fischer/lissom_fix

Allow Blue-RedGreen projection strength to vary with speed and dataset.
Added state_push/pop to ProjectionSheet to reset activities
Updated doc/reference_data submodule reference
Updated nbpublisher submodule reference
Updated doc/reference_data submodule reference
Added empty_storage_hook to analysis/__init__.py for use in topo profile

The use of lambda functions in notebook_setup.py was preventing
snapshots from being saved from the notebook environment.
Fixed CoordinateGrid SheetCoordinateSystem initialization
Updated dataviews submodule reference
Set default rows/cols to 11 in CFProjection.grid() to view central CF