Merge pull request #26 from xiangli-cmu/master

feat(controller) add dispatcher
Merge pull request #27 from xiangli-cmu/master

feat(controller) add dispatch AddInstanceEvent
Merge pull request #28 from xiangli-cmu/master

feat(controller) addListener
finish controller RPC
Merge branch 'master' of github.com:go-distributed/raccoon into dev

Conflicts:
	controller/controller.go
finish controller RPC test
Merge pull request #29 from fengjingchao/dev

Finish controller RPC
refactor instance into service/
Merge pull request #30 from fengjingchao/dev

refactor instance into service/

Made consensus on merge.
Separate net addr from instance.
finish two listener of LB
add load balancer test
router stop all services in Stop(); add lb test
refactor service-port map to app
Merge pull request #31 from fengjingchao/dev

Load balancer app prototype
fix instance
Merge pull request #33 from fengjingchao/dev

fix instance
add stats