Add more options for loading AWS credentials.
Default to /dev/xvdf if no devices found.
Add 'nobootwait' to mount options.

We don't want the instance to fail booting just because an EBS volume
is inaccessible.
Add more options for loading AWS credentials.
Merge branch 'master' of github.com:titanous/chef-ebs

Conflicts:
	recipes/volumes.rb
Merge branch 'master' into support-unencrypted-databags

Conflicts:
	recipes/volumes.rb
Merge pull request #7 from Shopify/support-unencrypted-databags

Support both encrypted and unencrypted databags.