merge from release-1.4 branch
merge from release-1.4 branch

James-Firth/pip,yati-sagade/pip,patricklaw/pip,cjerdonek/pip,esc/pip,prasaianooz/pip,RonnyPfannschmidt/pip,harrisonfeng/pip,willingc/pip,RonnyPfannschmidt/pip,erikrose/pip,chaoallsome/pip,ChristopherHogan/pip,xavfernandez/pip,squidsoup/pip,sigmavirus24/pip,prasaianooz/pip,supriyantomaftuh/pip,esc/pip,pypa/pip,alquerci/pip,davidovich/pip,fiber-space/pip,RonnyPfannschmidt/pip,wkeyword/pip,willingc/pip,mujiansu/pip,atdaemon/pip,pjdelport/pip,Gabriel439/pip,jamezpolley/pip,qbdsoft/pip,atdaemon/pip,James-Firth/pip,squidsoup/pip,James-Firth/pip,willingc/pip,sbidoul/pip,rouge8/pip,dstufft/pip,Gabriel439/pip,jmagnusson/pip,chaoallsome/pip,jmagnusson/pip,graingert/pip,sigmavirus24/pip,nthall/pip,esc/pip,caosmo/pip,jythontools/pip,mindw/pip,tdsmith/pip,rbtcollins/pip,zenlambda/pip,nthall/pip,qbdsoft/pip,ChristopherHogan/pip,dstufft/pip,pradyunsg/pip,tdsmith/pip,mindw/pip,Carreau/pip,alex/pip,rbtcollins/pip,ChristopherHogan/pip,patricklaw/pip,sbidoul/pip,habnabit/pip,erikrose/pip,natefoo/pip,jamezpolley/pip,benesch/pip,techtonik/pip,habnabit/pip,zvezdan/pip,alex/pip,benesch/pip,xavfernandez/pip,chaoallsome/pip,zvezdan/pip,habnabit/pip,rouge8/pip,atdaemon/pip,benesch/pip,luzfcb/pip,pypa/pip,pradyunsg/pip,yati-sagade/pip,squidsoup/pip,ncoghlan/pip,rouge8/pip,mindw/pip,h4ck3rm1k3/pip,blarghmatey/pip,natefoo/pip,mattrobenolt/pip,ncoghlan/pip,natefoo/pip,cjerdonek/pip,jasonkying/pip,mujiansu/pip,qbdsoft/pip,techtonik/pip,Gabriel439/pip,jmagnusson/pip,ianw/pip,msabramo/pip,h4ck3rm1k3/pip,yati-sagade/pip,fiber-space/pip,zenlambda/pip,supriyantomaftuh/pip,jasonkying/pip,minrk/pip,fiber-space/pip,h4ck3rm1k3/pip,graingert/pip,harrisonfeng/pip,jamezpolley/pip,qwcode/pip,pfmoore/pip,Ivoz/pip,blarghmatey/pip,haridsv/pip,Carreau/pip,pjdelport/pip,zorosteven/pip,alex/pip,luzfcb/pip,wkeyword/pip,haridsv/pip,alquerci/pip,mattrobenolt/pip,harrisonfeng/pip,jasonkying/pip,techtonik/pip,zorosteven/pip,msabramo/pip,wkeyword/pip,davidovich/pip,rbtcollins/pip,KarelJakubec/pip,KarelJakubec/pip,qwcode/pip,zorosteven/pip,nthall/pip,pjdelport/pip,davidovich/pip,minrk/pip,luzfcb/pip,graingert/pip,prasaianooz/pip,sigmavirus24/pip,erikrose/pip,caosmo/pip,blarghmatey/pip,zenlambda/pip,Ivoz/pip,tdsmith/pip,ianw/pip,caosmo/pip,pfmoore/pip,xavfernandez/pip,dstufft/pip,supriyantomaftuh/pip,KarelJakubec/pip,zvezdan/pip,mujiansu/pip,jythontools/pip,jythontools/pip,haridsv/pip,ncoghlan/pip