fix disk unit: 1K bytes is 1024 bytes instead of 1000 bytes

disk unit: 1K bytes is 1024 bytes instead of 1000 bytes

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>
Organize imports in all .py files

The imports must be in alphabetical order - that way we can avoid
duplicating imports.

And must follow the order:

1) Import common modules
import ...
import ...
from ... import ...
from ... import ...

2) Import kimchi modules
import kimchi.<mod>
import kimchi.<mod>
from kimchi import ...
from kimchi import ...

All Kimchi imports must be in section 2.
That way developer can easily identify them from common modules.

Signed-off-by: Aline Manera <alinefm@br.ibm.com>