Merge pull request #19 from lostcharlie/master

Module support updated
Merge pull request #20 from lostcharlie/master

Toolbar and HDFS support added.
Merge pull request #21 from lostcharlie/master

HDFS Restful service added.
Merge pull request #22 from lostcharlie/master

HDFS Explorer added.
Merge pull request #23 from lostcharlie/master

Refactoring
Merge pull request #24 from lostcharlie/master

Unit test stubs added.
Merge pull request #25 from lostcharlie/master

Change the flow style.
Merge pull request #26 from lostcharlie/master

Unit test added. User interface improved.
Merge pull request #27 from lostcharlie/master

User interface improved.
Merge pull request #28 from lostcharlie/master

Workflow engine support added.
Implement Oozie engin. Added type property to Module. Change the
packages name of hibernate beans to dto(data transfer object).
Merge pull request #29 from lostcharlie/master

Connection cannot be detached through dragging now.
Merge pull request #10 from justinliucs/master

Merge from base project.