Rename de_density to de_density_scale
Rename de_density to de_density_scale

The old name was potentially slightly ambiguous.  It sounded like
it might return the actual rho_de, when it really just returned
the redshift scaling.

joergdietrich/astropy,lpsinger/astropy,StuartLittlefair/astropy,mhvk/astropy,funbaker/astropy,AustereCuriosity/astropy,MSeifert04/astropy,stargaser/astropy,StuartLittlefair/astropy,kelle/astropy,pllim/astropy,joergdietrich/astropy,astropy/astropy,DougBurke/astropy,AustereCuriosity/astropy,larrybradley/astropy,DougBurke/astropy,StuartLittlefair/astropy,stargaser/astropy,kelle/astropy,tbabej/astropy,aleksandr-bakanov/astropy,pllim/astropy,dhomeier/astropy,dhomeier/astropy,funbaker/astropy,joergdietrich/astropy,kelle/astropy,astropy/astropy,stargaser/astropy,AustereCuriosity/astropy,pllim/astropy,larrybradley/astropy,bsipocz/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,astropy/astropy,mhvk/astropy,tbabej/astropy,astropy/astropy,MSeifert04/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,joergdietrich/astropy,tbabej/astropy,saimn/astropy,tbabej/astropy,AustereCuriosity/astropy,MSeifert04/astropy,lpsinger/astropy,joergdietrich/astropy,AustereCuriosity/astropy,bsipocz/astropy,saimn/astropy,saimn/astropy,pllim/astropy,funbaker/astropy,astropy/astropy,lpsinger/astropy,StuartLittlefair/astropy,stargaser/astropy,dhomeier/astropy,lpsinger/astropy,tbabej/astropy,larrybradley/astropy,mhvk/astropy,kelle/astropy,MSeifert04/astropy,dhomeier/astropy,bsipocz/astropy,saimn/astropy,kelle/astropy,bsipocz/astropy,DougBurke/astropy,saimn/astropy,aleksandr-bakanov/astropy,pllim/astropy,mhvk/astropy,mhvk/astropy,DougBurke/astropy,dhomeier/astropy,funbaker/astropy,larrybradley/astropy