Add support for resizing and mounting Btrfs filesystems
    
    As desktop variants of Fedora are now using Btrfs for the root
    filesystem, we need to be able to grow the Btrfs filesystem when
    the user requests to expand the filesystem to fill the card.
    
    Additionally, the installer script needs to be able to manipulate
    the contents of the root filesystem as needed to configure it for
    the target board.
    
    Reference: https://fedoraproject.org/wiki/Changes/BtrfsByDefault
    
    Signed-off-by: Neal Gompa <ngompa13@gmail.com>