Make Netty uses daemon thread for the bootstrap timer thread. Also fix the netty version.
Merge pull request #57 from continuuity/feature/fix-pending-hash-wheel-thread

Make Netty uses daemon thread for the bootstrap timer thread. Also fix the netty version.
Merge branch 'develop' of github.com:continuuity/weave into feature/multi-yarn-kerberos

Conflicts:
	core/src/main/java/com/continuuity/weave/internal/ServiceMain.java