scons: improve handling of optional plugin paths by only adding paths if a plugin will be built, prepending plugin paths to ensure linking against requested libs, and maintaining sorting of internal includes and libs given new plugin prepend behavior (addresses #250)
scons: improve handling of optional plugin paths by only adding paths if a plugin will be built, prepending plugin paths to ensure linking against requested libs, and maintaining sorting of internal includes and libs given new plugin prepend behavior (addresses #250)

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