scons: support passing multiple paths to PATH_REMOVE option - useful to strip - after the fact - paths that might come from pkg-config calls to cairo - closes #1980
scons: support passing multiple paths to PATH_REMOVE option - useful to strip - after the fact - paths that might come from pkg-config calls to cairo - closes #1980

jwomeara/mapnik,Mappy/mapnik,lightmare/mapnik,jwomeara/mapnik,mapycz/mapnik,davenquinn/python-mapnik,sebastic/python-mapnik,stefanklug/mapnik,rouault/mapnik,CartoDB/mapnik,kapouer/mapnik,manz/python-mapnik,tomhughes/python-mapnik,Uli1/mapnik,mapycz/python-mapnik,yiqingj/work,pnorman/mapnik,whuaegeanse/mapnik,manz/python-mapnik,yiqingj/work,rouault/mapnik,qianwenming/mapnik,Mappy/mapnik,zerebubuth/mapnik,pnorman/mapnik,mapycz/mapnik,sebastic/python-mapnik,jwomeara/mapnik,Airphrame/mapnik,jwomeara/mapnik,naturalatlas/mapnik,lightmare/mapnik,pramsey/mapnik,rouault/mapnik,garnertb/python-mapnik,mbrukman/mapnik,tomhughes/mapnik,CartoDB/mapnik,kapouer/mapnik,mapnik/python-mapnik,tomhughes/mapnik,davenquinn/python-mapnik,pramsey/mapnik,lightmare/mapnik,davenquinn/python-mapnik,mbrukman/mapnik,Airphrame/mapnik,mapnik/python-mapnik,Uli1/mapnik,whuaegeanse/mapnik,cjmayo/mapnik,kapouer/mapnik,mapnik/mapnik,garnertb/python-mapnik,pramsey/mapnik,stefanklug/mapnik,naturalatlas/mapnik,whuaegeanse/mapnik,yiqingj/work,Mappy/mapnik,CartoDB/mapnik,yohanboniface/python-mapnik,qianwenming/mapnik,kapouer/mapnik,garnertb/python-mapnik,tomhughes/mapnik,rouault/mapnik,lightmare/mapnik,yohanboniface/python-mapnik,mapycz/mapnik,qianwenming/mapnik,mapnik/mapnik,mapycz/python-mapnik,mapnik/mapnik,naturalatlas/mapnik,mbrukman/mapnik,cjmayo/mapnik,sebastic/python-mapnik,Uli1/mapnik,yiqingj/work,manz/python-mapnik,tomhughes/mapnik,Airphrame/mapnik,cjmayo/mapnik,whuaegeanse/mapnik,Uli1/mapnik,cjmayo/mapnik,qianwenming/mapnik,qianwenming/mapnik,mbrukman/mapnik,pnorman/mapnik,zerebubuth/mapnik,pramsey/mapnik,stefanklug/mapnik,tomhughes/python-mapnik,Mappy/mapnik,mapnik/python-mapnik,tomhughes/python-mapnik,Airphrame/mapnik,yohanboniface/python-mapnik,stefanklug/mapnik,zerebubuth/mapnik,mapnik/mapnik,pnorman/mapnik,naturalatlas/mapnik