Update URLs in manual.
Update URLs in manual.

berkley4/polipo,Psiphon-Inc/polipo,lkraider/polipo,dxq-git/polipo,fqtools/polipo,ssb22/polipo2,fqtools/polipo,nxtreaming/chumen,lkraider/polipo,feijilei/polipo,dxq-git/polipo,ssb22/polipo2,akkakks/polipo,jech/polipo,berkley4/polipo,ssb22/polipo2,galeksandrp/polipo,feijilei/polipo,akkakks/polipo,galeksandrp/polipo,nxtreaming/chumen,berkley4/polipo,fqtools/polipo,feijilei/polipo,jech/polipo,TierraDelFuego/opilop,lkraider/polipo,akkakks/polipo,dxq-git/polipo,jech/polipo,nxtreaming/chumen,ajmgh/polipo,galeksandrp/polipo,clowwindy/polipo