ENH: API change -- sort (columns=) instead of column=
ENH: API change -- sort (columns=) instead of column=

to be more adequate and correspond to provided docstring

kdebrab/pandas,louispotok/pandas,DGrady/pandas,louispotok/pandas,dsm054/pandas,harisbal/pandas,GuessWhoSamFoo/pandas,cython-testbed/pandas,amolkahat/pandas,kdebrab/pandas,DGrady/pandas,pratapvardhan/pandas,MJuddBooth/pandas,amolkahat/pandas,nmartensen/pandas,zfrenchee/pandas,jorisvandenbossche/pandas,datapythonista/pandas,amolkahat/pandas,rs2/pandas,jmmease/pandas,MJuddBooth/pandas,pratapvardhan/pandas,winklerand/pandas,TomAugspurger/pandas,datapythonista/pandas,amolkahat/pandas,jmmease/pandas,nmartensen/pandas,MJuddBooth/pandas,dsm054/pandas,cbertinato/pandas,zfrenchee/pandas,jorisvandenbossche/pandas,jorisvandenbossche/pandas,cython-testbed/pandas,gfyoung/pandas,winklerand/pandas,DGrady/pandas,toobaz/pandas,Winand/pandas,rs2/pandas,cbertinato/pandas,pandas-dev/pandas,amolkahat/pandas,GuessWhoSamFoo/pandas,toobaz/pandas,rs2/pandas,jmmease/pandas,nmartensen/pandas,linebp/pandas,cython-testbed/pandas,gfyoung/pandas,harisbal/pandas,linebp/pandas,jreback/pandas,kdebrab/pandas,TomAugspurger/pandas,pandas-dev/pandas,kdebrab/pandas,jreback/pandas,DGrady/pandas,louispotok/pandas,gfyoung/pandas,linebp/pandas,pandas-dev/pandas,cbertinato/pandas,louispotok/pandas,MJuddBooth/pandas,Winand/pandas,toobaz/pandas,nmartensen/pandas,harisbal/pandas,pratapvardhan/pandas,jreback/pandas,zfrenchee/pandas,dsm054/pandas,pratapvardhan/pandas,kdebrab/pandas,nmartensen/pandas,Winand/pandas,rs2/pandas,dsm054/pandas,linebp/pandas,winklerand/pandas,DGrady/pandas,gfyoung/pandas,harisbal/pandas,GuessWhoSamFoo/pandas,TomAugspurger/pandas,pratapvardhan/pandas,jreback/pandas,gfyoung/pandas,MJuddBooth/pandas,nmartensen/pandas,GuessWhoSamFoo/pandas,jmmease/pandas,pandas-dev/pandas,datapythonista/pandas,winklerand/pandas,toobaz/pandas,zfrenchee/pandas,cbertinato/pandas,jreback/pandas,zfrenchee/pandas,linebp/pandas,winklerand/pandas,cbertinato/pandas,toobaz/pandas,Winand/pandas,harisbal/pandas,Winand/pandas,TomAugspurger/pandas,jmmease/pandas,cython-testbed/pandas,DGrady/pandas,dsm054/pandas,jmmease/pandas,winklerand/pandas,linebp/pandas,GuessWhoSamFoo/pandas,cython-testbed/pandas,louispotok/pandas,jorisvandenbossche/pandas,Winand/pandas,datapythonista/pandas