If ec2 fact has ':' or '-', change to '_'

Change ec2 fact names with colons (:) or dashes (:) to undescore (_)
so that they can be used in templates.

Note that this makes copies instead of replacing the exisitng fact
names to avoid breaking existing playbooks.
Merge pull request #1954 from lorin/ec2-facts-fix

If ec2 fact has ':' or '-', change to '_'