Added SSL and HTTPS support.

I've attempted to add support for SSL (and HTTPS) config for the cookbook, mainly for use with riak_control. I'm a little new to chef so i'd appreciate any feedback.

The configuration is as simple as defining the attributes, for example in the ruby role file...

    default_attributes(
        "riak" => {
            "core" => {
                "https" => [[ "0.0.0.0", 8096 ]],
                "ssl" => {
                    "cert" => "MIICvTCCAiYCCQ.... CERT HERE",
                    "key" => "MIICXAIBA... KEY HERE"
                }
            }
        }
    )

I don't really know erlang, so I wasn't sure if the `[{..}]` in the `app.config` file signified there could me multiple ssl certificates, if so, I think this config structure should support it. Though I'm not sure how best to do that when i'd be important to also define file names for the key/cert pairs.