Sync oslo imageutils, strutils to Ironic

Changes in imageutils:
===============================
9e88af1 fixed typos found by RETF rules
b455fac Enable decimal value input in imageutils.QemuImgInfo
bec3a5e Implements SI/IEC unit system conversion to bytes
8b2b0b7 Use hacking import_exceptions for gettextutils._
aad179d Fixing misspelled encryption key in QemuImgInfo
12bcdb7 Remove vim header
2bd46eb Refactors byte size extraction logic
0356685 Adds common image utils

Changes in strutils:
====================
cb5a804 Move `mask_password` to strutils
8a0f567 Remove str() from LOG.* and exceptions
fd18c28 Fix safe_encode(): return bytes on Python 3
302c7c8 strutils: Allow safe_{encode,decode} to take bytes as input
bec3a5e Implements SI/IEC unit system conversion to bytes
e53fe85 strutils bool_from_string, allow specified default
8b2b0b7 Use hacking import_exceptions for gettextutils._
84d461e Fix a bug in safe_encode where it returns a bytes object in py3
12bcdb7 Remove vim header

Change-Id: If0d16d70c004344511b9851c8a533759f0d2bb52