Add IP address to error message of failed stack

The error message that occurs when the heat-script.sh or cfn-userdata
script runs doesn't include the IP address of the server, and it's not
possible to find that info in the stack-show output of a failed stack.
Add the IP address to the error message so it is displayed in the
stack-show output to aid in debugging.

Change-Id: I35bd4fbc1a05fa8207f3eb4f501f5becf78415c9
Ensure that the NoCloud data source is loaded, part 2

The cloud-init config is now in /etc/cloud/cloud.cfg.d/90_dpkg.cfg
instead of /etc/cloud/cloud.cfg.d/10_rackspace.cfg, and that caused bug
1285891 to resurface.

Change all files in /etc/cloud/cloud.cfg.d to make this somewhat
future-proof.

Change-Id: I65e2c0795952a5807783bf272061550a4a3447e0
Closes-Bug: #1288920
Closes-Bug: #1285891
Merge "Ensure that the NoCloud data source is loaded, part 2"
Merge "Add IP address to error message of failed stack"