Force size dimension display in output of btrfs-size.py via argument - KB, MB, GB

[MurzNN]

At now script auto-detect dimension for output size of disk - KB, MB, GB, etc.
This is not so good if we want to compare size of different disk, or parse and find large disks.
Please add command line argument to btrfs-size.py for force size output format, something like

btrfs-size.py --size-display=gb

[agronick]

This isn't a python script. Did you mean to put this on another repo?