Make sure we compile for Java 6.
Make sure we compile for Java 6.

OpenTSDB/asynchbase,pythian/asynchbase,yuzhu712/asynchbase,manolama/asynchbase,OpenTSDB/asyncbigtable,SteamShon/asynchbase,SteamShon/asynchbase,Connexity/asynchbase,angushe/asynchbase,hhshuai/asynchbase,manolama/asyncbigtable,manolama/asynchbase,adityakishore/asynchbase,tsuna/asynchbase,OpenTSDB/asynchbase,tempbottle/asynchbase,nvoron23/asynchbase,adityakishore/asynchbase,yuzhu712/asynchbase,mapr/asynchbase,angushe/asynchbase,Connexity/asynchbase,mapr/asynchbase,mway08/asynchbase,tempbottle/asynchbase,hhshuai/asynchbase,mway08/asynchbase,tsuna/asynchbase,nvoron23/asynchbase