add new ceph dashboard

add new ceph dashboard

this patch changes the ceph dashboard

now we show the information in a more graphical way, namely:

the overall status is displayed by a big icon (+health)
the warnings/errors are in a list (with severity)

we show more detailed information about monitors, osds, and pgs

we show the usage of the cluster as a gauge graph, and
the reads, writes and iops as running charts (the last 5 minutes)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>