bugfix: overflow of graphx Edge compare function

Author: Zhen Peng <zhenpeng01@baidu.com>

Closes #769 from zhpengg/bugfix-graphx-edge-compare and squashes the following commits:

8a978ff [Zhen Peng] add ut for graphx Edge.lexicographicOrdering.compare
413c258 [Zhen Peng] there maybe a overflow for two Long's substraction
[SQL] Implement between in hql

Author: Michael Armbrust <michael@databricks.com>

Closes #804 from marmbrus/between and squashes the following commits:

ae24672 [Michael Armbrust] add golden answer.
d9997ef [Michael Armbrust] Implement between in hql.
9bd4433 [Michael Armbrust] Better error on parse failures.