remove duplicate image
fix the multi-project build, pack single time
Merge pull request #72 from clockfly/master

fix the sbt pack, generate single package
split streaming to a new sub-project
seperate streaming to a new sub module
Merge pull request #73 from clockfly/master

seperate streaming to a new sub project
Merge remote-tracking branch 'upstream/master'

Conflicts:
	core/src/main/scala/org/apache/gearpump/cluster/ClusterMessage.scala
	project/Build.scala