#212, drop messages from zombie tasks
Merge remote-tracking branch 'upstream/master'

Conflicts:
	core/src/main/java/org/apache/gearpump/transport/netty/TaskMessage.java
fix #208 allow a app to run forever
Create CodeOfCommit.md
Merge remote-tracking branch 'upstream/master'
Merge pull request #236 from clockfly/general_app_submission

fix #208 allow a app to run forever
Merge remote-tracking branch 'upstream/master'
fix #237, add context information in log line