base.install: Adding lvm2 as based package

In fact, almost all systems needs to manage lvm devices. It's good to
have it available.
base.install: switching to local variables

Moving global variables to local ones. It's much more safer & easier to
read this way.
base: Removing lshw

lshw is only required for pxe & health images, no need to have it on
base though.
build: Fixing invalid file with pxe & health

Let's change a little bit how cleanup is handled.
To insure packages are properly saved, we need to let pxe & health
asking a specific task unless calling it at cleanup time is too late
since dpkg & co got removed.

This patch adds a MAKEFILE_TARGET variable we catch at cleanup time and
if we are on health or pxe targets, we just ignore those file creation.