[SPARK-1754] [SQL] Add missing arithmetic DSL operations.

Add missing arithmetic DSL operations: `unary_-`, `%`.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #689 from ueshin/issues/SPARK-1754 and squashes the following commits:

a09ef69 [Takuya UESHIN] Add also missing ! (not) operation.
f73ae2c [Takuya UESHIN] Remove redundant tests.
5b3f087 [Takuya UESHIN] Add tests relating DSL operations.
e09c5b8 [Takuya UESHIN] Add missing arithmetic DSL operations.