TAJO-1021: Refactor StorageManager to use reflection for scanner and appender

https://dbserver.korea.ac.kr/jira/browse/TAJO-1021
Merge pull request #2 from hyunsik/TAJO-1021

TAJO-1021: Refactor StorageManager to use reflection for scanner and app...
Updated the project home and repository urls.
Merge branch 'master' of github.com:tajo-project/tajo into DQEP
Improved SQLAnalyzer to recognize complex join clause.
Added initial join enumeration code.