use std::string as is convention and comment last bit of unused mutex support in connection manager
use std::string as is convention and comment last bit of unused mutex support in connection manager

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