Display correct defaults (incorporating defaults from pip.conf) for src_dir and build_dir in pip install --help output
Display correct defaults (incorporating defaults from pip.conf) for src_dir and build_dir in pip install --help output

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