Merge pull request #410 from s0undt3ch/develop

Add information to the docs about the `EC2.delvol_on_destroy` "global" setting.
Merge pull request #411 from s0undt3ch/develop

Allow configuring the deploy setting on the provider's configuration.
Merge pull request #412 from s0undt3ch/develop

Document the recently added options regarding the `deploy` setting.
When failing to get node data, return a dict instead of just false.
Also catch `IOError`'s and log them when verifying the environment.