Manual device mounting made easy.

This is a wrapper script for `udisksctl` making it more convenient to use.

Usage:
    `udisk` (or `udisk status`) - prints actual mountable devices instead of just "sda", "sdb", etc.
    `udisk wait`                - waits for new device to appear then prints status
    `udisk mount /dev/sda1`     - does the same as `udisksctl mount -b /dev/sda1`
    `udisk umount /dev/sda1`    - does the same as `udisksctl unmount -b /dev/sda1`
                                  (but with `umount` instead of `unmount`)