new option --preserve, -p is added

Also fix some bug in PipeFile

This commit introduce remote repository and file accross ssh

We now use PipeFile to handle complex file type and compute md5 and filesize.

This commit add the following features in installsystems:
- A download progress bad
- check size before download
- check size after download
- check md5 after download

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>

Seblu: Fix too many things...

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>

best mode search best version across all repo and not the first

This is a better way of doing things. This help to have a better display of
where is causing latency

this allow to register breaked or offline repository wihtou breaking all is

THis is very useful to be able to list it !

new syntax is available [repo/]image[:version]
first command updated is delete

This also change underlying way of initiliaze a repository.
A repository can now be defined and be innaccessible

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>