Extends COMMIT parameters with git hash in make system

We can define the exact commit hash or branch that
want to use for building packages from.

Value should be defined in config.mk with format:
 REPONAME_COMMIT?=branch
  or
 REPONAME_COMMIT?=hash
for example:
 FUELLIB_COMMIT?=stable/5.1
 FUELLIB_COMMIT?=203ef3179007cffe3236032e61ecbaf1cd20605f

Change-Id: Ifa225003f03dfa41028abb6db0a5ac83ad22f81e
Close-bug: #1364076
Fixes a bug with filename extension during .vdi creation.

Change-Id: Ib1a7b0256d8961946e844f265667053e5e422d9b
Closes-Bug: 1376429
Some functions in vbox scripts relied on language specific output.

Change-Id: I1c4be75336c2a8150f8f73a628185df2de19b16c
Closes-Bug: 1376434
Merge "Extends COMMIT parameters with git hash in make system"
Merge "Some functions in vbox scripts relied on language specific output."
Merge "Fixes a bug with filename extension during .vdi creation."
Building OS images centos and ubuntu

Those images are supposed to be used for
image based provisioning. This patch set
needs python-imgcreate package to be available.

Implements: blueprint image-based-provisioning
Change-Id: I4f038c99d4caf7d2b6e291bff29572b3a45d92c7
Add ability to build separate fs images for ubuntu

This ability required to build images for every separate mountpoint needed.
Eg. /boot, /var, /var/lib, etc.
File system support is limited to ext2, ext3, ext4 only. No XFS.

Implements: blueprint image-based-provisioning
Change-Id: I650052154fe7b483aaba89389e9a09f80fc1543e