Fix append queue telemetry and parameterize sizes.

The original append queue telemetry never worked, because it was
updated only upon the exit of the select statement, which would
usually liberate the queues of contents.  This has been fixed to
be reported arbitrarily.

The queue sizes are now parameterizable via flags.
Custom Comparator for SampleKey Varint Encoding.

The SampleKey DTO now uses varints for space savings and reducing
the complexity of the places where it is interfaced with having to
bigendian encode 64-bits.

The make infrastructure has been greatly improved to unify Travis and
the standard builds and keep side effects partitioned.
Update workflow documentation.
No TCMALLOC.
Add per graph auto-refresh option to web UI.

This adds a drop-down menu to select/disable a auto-refresh interval.