making it possible to build polipo using MinGW-w64
making it possible to build polipo using MinGW-w64

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