JSON Table (WIP)

Adding the possibility to specify tables directly from JSON without
specifying the header. Supports the following notation:

	"0" : {
  		"type" : "JsonTable",
  		"names" : ["A", "B", "C"],
  		"types" : ["INTEGER", "STRING", "FLOAT"],
  		"groups" : [3],
  		"useStore" : true
  	}

Follows the same properties as the TableBuilder class that is used below. Furthermore,
it has the useStore flag to indicate if the result should be a Store class with the
default Merge set.