TAJO-1195: Remove unused CachedDNSResolver Class. (DaeMyung Kang via jaehwa)

Closes #253
TAJO-1197: Unit test failed: unable to create new native thread. (jinho)

Closes #255
TAJO-1200: Invalid shuffle data of multiple worker in same server. (jinho)

Closes #259
TAJO-1181: Avro schema URL should support various protocols. (jinho)

Closes #252
TAJO-1205: Remove possible memory leak in TajoMaster. (jinho)

Closes #265
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into TAJO-1033
TAJO-1208: Failure of create table using textfile on hivemeta. (jinho)

Closes #270
TAJO-1163: TableDesc should use URI instead of Path.

Closes #235
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into TAJO-1033