Make the alarm actions run in one thread

bug #1131024
Change-Id: I678d8919a17fc73350ec9061ad2a7234e1d6b9f6
Update the metadata if an alarm action makes changes

The point of this change?
- You have another instances' ip in your metadata and if it
  gets restarted you want cfn-hup to see the new ip.

How is it achieved?
- poll for the metadata so you can see these changes (cfn-hup)
- when ever an alarm action is run we make sure the metadata is refreshed.

bug #1131024
Change-Id: I0798c4da9689b126c3c98cafa63138ff2c484ea9
Merge "Make the alarm actions run in one thread"
Merge "Update the metadata if an alarm action makes changes"