add PATH_INSERT option to allow pre-appending a PATH variable for finding programs like pkg-config and freetype-config and allow it and PKG_CONFIG_PATH setting to work with relative paths by completing dynamically
add PATH_INSERT option to allow pre-appending a PATH variable for finding programs like pkg-config and freetype-config and allow it and PKG_CONFIG_PATH setting to work with relative paths by completing dynamically

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