Adds support for iPXE scripting. Allows for the
operator to specify a remote iPXE kernel to pull in
newer iPXE kernel features and specify a remote
default iPXE script for customizing the multi node
for other types of deployments.
Switches the installations to use netboot installer kernels
instead of ISO retrival and extraction.
Restructures directory to allow for future multi node configs
instead of just debian based installs.
Change-Id: Ie97f021dbd33ad3d852132b0b2850f54d4e13476
f00c6bf215