TAJO-757: Add parser rule and algebraic expression for window function. (hyunsik)
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into window_function

Conflicts:
	CHANGES.txt
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into window_function
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into window_function
TAJO-800: CLI's meta command should be aware "TABLE_NAME" style. (Hyoungjun Kim via hyunsik)
TAJO-813: CLI should support comment character with multi-line query. (Hyoungjun Kim via hyunsik)
TAJO-820: Add missing license header to 0.8.0 release announcement. (hyunsik)
TAJO-814: Set up Travis CI builds.

Fixes #8.
TAJO-817: tajo-core should not skip deploy.

Closes #7.
TAJO-807: Implement Round(numeric, int) function. (Seungun Choe via hyunsik)
TAJO-494: Extend TajoClient to run a query with a plan context serialized as the JSON form. (jihoon)
TAJO-803: INSERT INTO without FROM throws ClassCastException. (Hyoungjun Kim via hyunsik)
TAJO-823: Missing INET4 handling in DatumFactory.cast(). (jihoon)
TAJO-816: NULL delimiter doesn't apply with HCatalogStore. (jaehwa)
TAJO-829: Same constants in groupby clause may cause planning error.
TAJO-801: Multiple distinct should be supported. (Hyoungjun Kim via hyunsik)
TAJO-811: add simple fifo scheduler support. (jinho)
TAJO-833
TAJO-821: IllegalStateException occurs when a NettyClientBase object is created within single thread. (hyoungjunkim via jinho)
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into window_function

Conflicts:
	CHANGES
	tajo-algebra/src/main/java/org/apache/tajo/algebra/Expr.java