m5nr api: added option to filter search by source
m5nr api: added option to filter search by source

wilke/MG-RAST,wilke/MG-RAST,MG-RAST/MG-RAST,MG-RAST/MG-RAST,wilke/MG-RAST,teharrison/MG-RAST,teharrison/MG-RAST,paczian/MG-RAST,MG-RAST/MG-RAST,teharrison/MG-RAST,paczian/MG-RAST,teharrison/MG-RAST,paczian/MG-RAST,teharrison/MG-RAST,teharrison/MG-RAST,paczian/MG-RAST,MG-RAST/MG-RAST,MG-RAST/MG-RAST,wilke/MG-RAST,wilke/MG-RAST,wilke/MG-RAST,wilke/MG-RAST,paczian/MG-RAST,paczian/MG-RAST