Client

Created client to connect to S-Store and make calls to the predefined stored procedures
Take JSON messages of the form { "proc": ProcedureName, "args": [ arg1, arg2, ... ]  }
Returns JSON messages of the form { "data": [ "colname1": $val, "colname2": $val ... ], "success": 0/1 }
Maybe a debugging println that ought to be removed?