More chkconfig magic would be helpful

Related to #59 

If `advanced.config` contains a simple tuple without an enclosing array, the error looks like this:

````
escript: exception error: no function clause matching
                 lists:foldl(#Fun<cuttlefish_advanced.0.102210937>,
                             [{yokozuna,
                               [{root_dir,"./data/yz"},
                                {anti_entropy_data_dir,
                                 "./data/yz_anti_entropy"},
                                {solr_jvm_opts,
                                 "-d64 -Xms1g -Xmx1g -XX:+UseStringCache -XX:+UseCompressedOops"},
                                {solr_jmx_port,8985},
````