added MySQL backend to plugin
added MySQL backend to plugin

avorio/rdflib,dbs/rdflib,RDFLib/rdflib,dbs/rdflib,dbs/rdflib,dbs/rdflib,ssssam/rdflib,yingerj/rdflib,RDFLib/rdflib,marma/rdflib,armandobs14/rdflib,avorio/rdflib,ssssam/rdflib,avorio/rdflib,armandobs14/rdflib,yingerj/rdflib,marma/rdflib,armandobs14/rdflib,ssssam/rdflib,armandobs14/rdflib,RDFLib/rdflib,avorio/rdflib,RDFLib/rdflib,ssssam/rdflib,yingerj/rdflib,marma/rdflib,yingerj/rdflib,marma/rdflib