expose function to force garbage collection in v8 (purely for testing)
expose function to force garbage collection in v8 (purely for testing)

CartoDB/node-mapnik,mapnik/node-mapnik,MaxSem/node-mapnik,tomhughes/node-mapnik,Uli1/node-mapnik,Uli1/node-mapnik,MaxSem/node-mapnik,langateam/node-mapnik,langateam/node-mapnik,stefanklug/node-mapnik,tomhughes/node-mapnik,gravitystorm/node-mapnik,CartoDB/node-mapnik,mapnik/node-mapnik,mapnik/node-mapnik,tomhughes/node-mapnik,CartoDB/node-mapnik,stefanklug/node-mapnik,langateam/node-mapnik,Uli1/node-mapnik,mojodna/node-mapnik,CartoDB/node-mapnik,mojodna/node-mapnik,stefanklug/node-mapnik,gravitystorm/node-mapnik,stefanklug/node-mapnik,langateam/node-mapnik,mapnik/node-mapnik,mojodna/node-mapnik,langateam/node-mapnik,gravitystorm/node-mapnik,mojodna/node-mapnik,CartoDB/node-mapnik,MaxSem/node-mapnik,Uli1/node-mapnik,MaxSem/node-mapnik,gravitystorm/node-mapnik,tomhughes/node-mapnik,tomhughes/node-mapnik,mapnik/node-mapnik