added docs for new maxCache, arraysize features on SQLTable, SQLTableClustered
added docs for new maxCache, arraysize features on SQLTable, SQLTableClustered

theoryno3/pygr,theoryno3/pygr,cjlee112/pygr,cjlee112/pygr,ctb/pygr,RitwikGupta/pygr,ctb/pygr,GenDataPro/pygr,ctb/pygr,RitwikGupta/pygr,RitwikGupta/pygr,cjlee112/pygr,cjlee112/pygr,GenDataPro/pygr,ctb/pygr,GenDataPro/pygr,theoryno3/pygr,ctb/pygr