MAINT: Refactor numpy.ma.where.
MAINT: Refactor numpy.ma.where.

Use np._NoValue as default values of 'x' and 'y' in signature. That
allows None values to be used for compatibility with the unmasked
version of where and makes detection of the case when neither is
given easier.

Use properties *.data and *.mask instead of *._data and *._mask. That
may avoid some subtle problems.

Minor style cleanups.

mingwpy/numpy,dimasad/numpy,ChanderG/numpy,ekalosak/numpy,jorisvandenbossche/numpy,jankoslavic/numpy,WarrenWeckesser/numpy,CMartelLML/numpy,mhvk/numpy,rgommers/numpy,MaPePeR/numpy,ViralLeadership/numpy,MSeifert04/numpy,musically-ut/numpy,hainm/numpy,skymanaditya1/numpy,drasmuss/numpy,nbeaver/numpy,ChristopherHogan/numpy,endolith/numpy,bringingheavendown/numpy,BabeNovelty/numpy,rajathkumarmp/numpy,abalkin/numpy,Eric89GXL/numpy,AustereCuriosity/numpy,empeeu/numpy,MaPePeR/numpy,gmcastil/numpy,argriffing/numpy,MSeifert04/numpy,stuarteberg/numpy,tdsmith/numpy,BabeNovelty/numpy,rajathkumarmp/numpy,mingwpy/numpy,pbrod/numpy,solarjoe/numpy,Dapid/numpy,endolith/numpy,pizzathief/numpy,empeeu/numpy,leifdenby/numpy,mwiebe/numpy,Linkid/numpy,bmorris3/numpy,WillieMaddox/numpy,MSeifert04/numpy,utke1/numpy,bmorris3/numpy,ContinuumIO/numpy,bertrand-l/numpy,chiffa/numpy,MichaelAquilina/numpy,behzadnouri/numpy,shoyer/numpy,AustereCuriosity/numpy,pyparallel/numpy,mortada/numpy,mattip/numpy,simongibbons/numpy,mhvk/numpy,jankoslavic/numpy,GrimDerp/numpy,dato-code/numpy,tynn/numpy,pizzathief/numpy,chatcannon/numpy,charris/numpy,pizzathief/numpy,SiccarPoint/numpy,dwillmer/numpy,cowlicks/numpy,ddasilva/numpy,grlee77/numpy,abalkin/numpy,hainm/numpy,Yusa95/numpy,Srisai85/numpy,jonathanunderwood/numpy,nguyentu1602/numpy,pdebuyl/numpy,dimasad/numpy,SunghanKim/numpy,njase/numpy,Eric89GXL/numpy,Srisai85/numpy,mortada/numpy,njase/numpy,tdsmith/numpy,ChristopherHogan/numpy,KaelChen/numpy,gfyoung/numpy,rudimeier/numpy,seberg/numpy,endolith/numpy,jakirkham/numpy,grlee77/numpy,joferkington/numpy,tacaswell/numpy,has2k1/numpy,AustereCuriosity/numpy,abalkin/numpy,jakirkham/numpy,jorisvandenbossche/numpy,grlee77/numpy,empeeu/numpy,trankmichael/numpy,gfyoung/numpy,musically-ut/numpy,jorisvandenbossche/numpy,drasmuss/numpy,mattip/numpy,rhythmsosad/numpy,groutr/numpy,mingwpy/numpy,musically-ut/numpy,Srisai85/numpy,chatcannon/numpy,hainm/numpy,groutr/numpy,behzadnouri/numpy,WarrenWeckesser/numpy,sigma-random/numpy,Linkid/numpy,rgommers/numpy,sigma-random/numpy,dimasad/numpy,BMJHayward/numpy,ahaldane/numpy,BMJHayward/numpy,SiccarPoint/numpy,WarrenWeckesser/numpy,charris/numpy,bertrand-l/numpy,pdebuyl/numpy,dwillmer/numpy,sinhrks/numpy,bmorris3/numpy,rherault-insa/numpy,mhvk/numpy,ssanderson/numpy,bringingheavendown/numpy,b-carter/numpy,mattip/numpy,jschueller/numpy,dato-code/numpy,jakirkham/numpy,rudimeier/numpy,pyparallel/numpy,argriffing/numpy,mathdd/numpy,anntzer/numpy,ekalosak/numpy,jakirkham/numpy,ChanderG/numpy,SiccarPoint/numpy,kiwifb/numpy,anntzer/numpy,GrimDerp/numpy,musically-ut/numpy,ESSS/numpy,mathdd/numpy,cowlicks/numpy,felipebetancur/numpy,SiccarPoint/numpy,simongibbons/numpy,bringingheavendown/numpy,njase/numpy,nguyentu1602/numpy,anntzer/numpy,pyparallel/numpy,GaZ3ll3/numpy,jakirkham/numpy,stuarteberg/numpy,rgommers/numpy,moreati/numpy,argriffing/numpy,pbrod/numpy,MichaelAquilina/numpy,KaelChen/numpy,sinhrks/numpy,ContinuumIO/numpy,ViralLeadership/numpy,hainm/numpy,solarjoe/numpy,shoyer/numpy,ChanderG/numpy,maniteja123/numpy,behzadnouri/numpy,dato-code/numpy,mortada/numpy,has2k1/numpy,Dapid/numpy,tynn/numpy,dimasad/numpy,ahaldane/numpy,joferkington/numpy,charris/numpy,simongibbons/numpy,skymanaditya1/numpy,KaelChen/numpy,rajathkumarmp/numpy,shoyer/numpy,GrimDerp/numpy,numpy/numpy,tynn/numpy,BMJHayward/numpy,cjermain/numpy,tdsmith/numpy,mhvk/numpy,gmcastil/numpy,sigma-random/numpy,leifdenby/numpy,rudimeier/numpy,pbrod/numpy,felipebetancur/numpy,bmorris3/numpy,kirillzhuravlev/numpy,utke1/numpy,sinhrks/numpy,mathdd/numpy,cjermain/numpy,seberg/numpy,Yusa95/numpy,nguyentu1602/numpy,nbeaver/numpy,cjermain/numpy,has2k1/numpy,sonnyhu/numpy,Anwesh43/numpy,anntzer/numpy,trankmichael/numpy,simongibbons/numpy,mattip/numpy,kirillzhuravlev/numpy,SunghanKim/numpy,Anwesh43/numpy,ahaldane/numpy,WarrenWeckesser/numpy,jschueller/numpy,ChristopherHogan/numpy,GaZ3ll3/numpy,githubmlai/numpy,madphysicist/numpy,ssanderson/numpy,KaelChen/numpy,rudimeier/numpy,Linkid/numpy,has2k1/numpy,rajathkumarmp/numpy,ContinuumIO/numpy,jonathanunderwood/numpy,kirillzhuravlev/numpy,CMartelLML/numpy,joferkington/numpy,Anwesh43/numpy,MichaelAquilina/numpy,pbrod/numpy,WillieMaddox/numpy,kirillzhuravlev/numpy,pbrod/numpy,ekalosak/numpy,pdebuyl/numpy,pizzathief/numpy,dwillmer/numpy,jankoslavic/numpy,MichaelAquilina/numpy,grlee77/numpy,felipebetancur/numpy,seberg/numpy,BabeNovelty/numpy,moreati/numpy,b-carter/numpy,jonathanunderwood/numpy,ahaldane/numpy,shoyer/numpy,GaZ3ll3/numpy,BabeNovelty/numpy,Srisai85/numpy,skwbc/numpy,tacaswell/numpy,Eric89GXL/numpy,ChanderG/numpy,leifdenby/numpy,simongibbons/numpy,numpy/numpy,cowlicks/numpy,dwillmer/numpy,maniteja123/numpy,dato-code/numpy,rherault-insa/numpy,CMartelLML/numpy,ESSS/numpy,nguyentu1602/numpy,ChristopherHogan/numpy,githubmlai/numpy,madphysicist/numpy,kiwifb/numpy,mingwpy/numpy,trankmichael/numpy,rhythmsosad/numpy,charris/numpy,b-carter/numpy,felipebetancur/numpy,maniteja123/numpy,ssanderson/numpy,shoyer/numpy,rhythmsosad/numpy,ekalosak/numpy,GrimDerp/numpy,mortada/numpy,madphysicist/numpy,sigma-random/numpy,Eric89GXL/numpy,skwbc/numpy,ahaldane/numpy,groutr/numpy,sonnyhu/numpy,sonnyhu/numpy,grlee77/numpy,githubmlai/numpy,gfyoung/numpy,stuarteberg/numpy,WarrenWeckesser/numpy,skymanaditya1/numpy,MSeifert04/numpy,ddasilva/numpy,utke1/numpy,jorisvandenbossche/numpy,jschueller/numpy,seberg/numpy,mwiebe/numpy,jorisvandenbossche/numpy,chatcannon/numpy,Dapid/numpy,sinhrks/numpy,MaPePeR/numpy,Yusa95/numpy,cjermain/numpy,pizzathief/numpy,chiffa/numpy,githubmlai/numpy,trankmichael/numpy,BMJHayward/numpy,solarjoe/numpy,stuarteberg/numpy,SunghanKim/numpy,GaZ3ll3/numpy,ViralLeadership/numpy,rhythmsosad/numpy,Linkid/numpy,SunghanKim/numpy,ESSS/numpy,drasmuss/numpy,kiwifb/numpy,numpy/numpy,moreati/numpy,skwbc/numpy,mhvk/numpy,CMartelLML/numpy,joferkington/numpy,tdsmith/numpy,Yusa95/numpy,skymanaditya1/numpy,pdebuyl/numpy,sonnyhu/numpy,nbeaver/numpy,WillieMaddox/numpy,MaPePeR/numpy,gmcastil/numpy,endolith/numpy,tacaswell/numpy,ddasilva/numpy,mwiebe/numpy,bertrand-l/numpy,mathdd/numpy,jankoslavic/numpy,jschueller/numpy,empeeu/numpy,cowlicks/numpy,rherault-insa/numpy,rgommers/numpy,madphysicist/numpy,chiffa/numpy,madphysicist/numpy,numpy/numpy,Anwesh43/numpy,MSeifert04/numpy