GitLab

Also fix various typos

Add a section under Architecture about the Image Configuration Tasks

Fill in the usage section of the documentation

Fill in the architecture section of the documentation

Remove xen-linux-system-3.2.0-4-amd64 package and add packages from
the wheezy-helper suite of apt.dev.grnet.gr

It is no longer needed for the wheezy helper

Replace the meta packages with the real multistrap packages in
multistrap.conf

Put linux-image-amd64 and xen-linux-system-amd64 in the GRNet section
of multistrap.conf

Repo and version pinning does not work yet

Rename snf-image-create-fixed-helper script to snf-image-create-helper.
Also remove the command that will create a tar archive of the helper
files under /tmp

Conflicts:
	version

This can be used to overwrite the default HELPER_URL

Make it reflect the current state

Url must be parsed before checked against LocationURL. This commit
fixes this by parsing the url at the beggining.

s/in/is/

When you run snf-image-create-fixed-helper an archive of the fixed
helper is created under /tmp

Move the old snf-image-update-helper to snf-image-create-fixed-helper
and make the new snf-image-update-helper download a fixed helper image
specified by the HELPER_URL variable.

Update pithcat to initialize the Pithos ModularBackend differently,
based on the type of the requested image URL. Specifically, in case the
image URL if a 'pithosmap' URL, no access to the database is needed. So
in this case, the backend must be initialized with 'None' database
connection URL.