Allow TTL to be specified when using `sl cci dns sync`
Remove hardcoded references to DNS TTL of 7200

Also more consistent with existing DNS docblocks.
Merge pull request #191 from briancline/cci-dns-sync-ttl

Allow TTL to be specified when using `sl cci dns sync`
Adds Filtering by label for SSH key listings
Merge pull request #193 from sudorandom/sshkey_resolve_id

Adds Filtering by label for SSH key listings