Deprecate untrustworthy fns
Deprecate untrustworthy fns

calculate_slope_aspect_at_nodes_burrough() has decayed and needs some
love - it gives wrong answers as of right now, though is salvageable.

I deprecated Katy’s old slope function, as I think calc_slope_of_node()
now entirely supersedes it.

SiccarPoint/landlab,Carralex/landlab,amandersillinois/landlab,RondaStrauch/landlab,ManuSchmi88/landlab,csherwood-usgs/landlab,csherwood-usgs/landlab,Carralex/landlab,cmshobe/landlab,Carralex/landlab,cmshobe/landlab,ManuSchmi88/landlab,ManuSchmi88/landlab,landlab/landlab,RondaStrauch/landlab,RondaStrauch/landlab,laijingtao/landlab,cmshobe/landlab,landlab/landlab,laijingtao/landlab,SiccarPoint/landlab,amandersillinois/landlab,landlab/landlab