Don't pass in the common var file.
Add tags to server security groups so abbey can find them easily.
Figure out the security group for the play by tag instead of getting it passed in.
Remove PropagateAtLaunche from security groups.
Add a play tag to subnets that house application servers.
Fix a typo.
Merge pull request #726 from edx/feanil/mckinsey_abbey

Feanil/mckinsey abbey