Fix issue with the new bucky-based event selector

* syntax error
* fix error in var name
* error in variable name
* index for alias selection was wrong.
Make a bit of room in overview dashboard.

We need to squish in NTP somehow. We know what memory sizes et al are,
so no need for a lot of the y-axis labels.
Add an NTP time offset graph in overview.

Poor time management is largely out of our control, and can cause
significant issues that can be hard to debug.

Promote NTP to a top-level graph, so we are immediately alerted of
any weirdness.