Change setup stack states with signals

This pull request adds the following functionality:

- Change setup stack states with signals so that it can be controlled whether changing from one state to another is permitted or not for the setup stack.

My ICLA is listed under "Furkan Bıçak"
While doing this test, I have set up a stack with 2 runners and then destroyed which caused the registered stack to be removed. Therefore, after setting up a stack with 4 runners worked. When I realize this point, I have tried deploying with 2 runners and setting up the stack with 4 runners, it did not work as expected. Sorry about this fault and here is the PR that fixes this issue: https://github.com/usergrid/usergrid/pull/237