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>

seblu: fix some code

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

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

This can be avoided by -p