Add and update vars.

Add a new overridable var for the ORA2_FILE_PREFIX and
update the default value of the newrelic application names.
Update the xqueue as well to use the edp convention.
Update xqueue watcher as well.
Merge pull request #1254 from edx/feanil/new_ora_var

Add and update vars.
Remove the refs/tags seperation.

Instead, we take any extra_vars that have a suffix of '_version' and
make sure those exist as tags on the AMI. All other vars do not get
saved anywhere.

Turn on instance tagging with abbey.
Optionally tag instances when roles deploy code.

The instance gets tagged with the repo and hash that was deployed.