Take iSCSI deploy out of pxe driver

This commit aims at separating the iSCSI deploy portions
from pxe driver so that it can reused in the newly proposed
iLO virtualmedia driver.

Implements: blueprint ironic-ilo-virtualmedia-driver
Change-Id: Id0a4b0fab797c884448a27b1cd5e3a1da05786a7
Add support for creating vfat disk images

This commit introduces support for creating temporary
small vfat images in ironic which will be used for
passing information to baremetal node using virtual
media through OOB channel.

Change-Id: I42b88da02090aec310f567642d3174d0f482b585
Implements: blueprint ironic-ilo-virtualmedia-driver
Add support for interacting with swift

This commit introduces support for interacting with
swift for creating and deleting swift objects. This
will be initially used by ilo driver for hosting
temporary floppy images.

Change-Id: I9a3962820b7e18fb1014be1e43cb107facfede9f
Implements: blueprint ironic-ilo-virtualmedia-driver
IloVirtualMediaIscsi deploy driver

This commit introduces a new deploy driver which uses iLO virtual
media to boot up proliant baremetal nodes, and uses iSCSI to deploy
the baremetal nodes.

Change-Id: I98f47ed6082a3a28fce3148f6d5177cdb5c61881