Making ColumnDataSource __init__ automatically handle a dict positional argument, without requiring passing it in explicitly via kwargs as "data={…}"
make _match_data_params handle dict arguments for dataspec values
Moving some helper functions in GlyphFunction further down, and renaming them to have a leading underscore
Renaming GlyphRenderer.dataspecs to dataspecs_with_refs, and making it a class method on HasProps; adding another dataspecs() classmethod