add --openstack-config-drive option to process metadata and
userdata using as datasource an openstack config drive
(iso9660 or vfat filesystem)
add type_by_device function to get the disk type
add blkid library
functions:
* disk_for_path: is a useful function to get
the disk path where a specific is mounted
for instance: / -> /dev/sda
* disk_resize_grow: resizes/grows partitions and filesystems
this function uses the last disk partition/filesystem
for resize it