riemann: Increase default TTL and expiration delays

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
collectd: Separate rated & unrated metrics

Use two Riemann targets: one for time-rated metrics, another for raw
ones. Send the sshd stuff to the unrated one, the rest (by default) to
time-rated.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
riemann-dash: Drop the sshd time series chart

Now that we have a non-time-rated value, there is no need for the chart.
Save space by removing it.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Do the scaling on the collectd side

Instead of doing the scaling in Riemann, do it on the collectd side.
Tiny bit more load on the clients, less work on the server. Adjust the
thresholds and the dashboard accordingly.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>