Automatically detect mountpoint for iocage (#80)

* automate grabbing iocage dataset instead of hardcoding

* move iocage dataset define to jailman.sh instead of config.yml
It can still be overriden by config.yml

config.yml.example

@@ -3,8 +3,6 @@ global:
   dataset:
    # dataset for internal jail config files
    config: tank/apps
-   # Iocage root dataset
-   iocage: tank/iocage
    # Media library dataset
    media: tank/media
    # Parent downloads dataset 

jailman.sh

@@ -84,6 +84,9 @@ while getopts ":i:r:u:d:g:h" opt
      esac
 done
 
+global_dataset_iocage=$(zfs get -H -o value mountpoint $(iocage get -p)/iocage)
+global_dataset_iocage=${global_dataset_iocage#/mnt/}
+
 # Parse the Config YAML
 for configpath in ${SCRIPT_DIR}/jails/*/config.yml; do ! eval $(parse_yaml ${configpath}); done
 eval $(parse_yaml config.yml)