TAJO-1238: Add SET SESSION and RESET statement.

Closes #294
TAJO-1143: TajoMaster, TajoWorker, and TajoClient should have diagnosis phase at startup

Closes #280
TAJO-1244: tajo.worker.tmpdir.locations should use a validator for a list of Path.

Closes #298
TAJO-1243: *-site.xml.template should have default configs commented out.

Closes #297
Change documentaiton url of devel and current versions.
TAJO-1241: Change documentaiton url of devel and current versions.

Closes #295
TAJO-1233: Merge hbase_storage branch to the master branch. (Hyoungjun Kim via hyunsik)

Closes #288
Add missed a commit log to CHANGES.
TAJO-1239 ORDER BY with null column desc miss some data. (Hyoungjun Kim via hyunsik)

Closes #299
Fix a wrong documentation link in user doc.
TAJO-1242: Json scanner can not read some case of trucated text. (jinho)

Closes #296
Fix the broken unit test of TAJO-1242
Merge branch 'master' of http://git-wip-us.apache.org/repos/asf/tajo into index_support