pip.download: refactor and try to clarify
pip.download: refactor and try to clarify

add _check_download_dir and _download_http_url to ease the understanding
of unpack_http_url and unpack_file_url functions

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