We are tracking latencies in microseconds, but almost everywhere else
they are reported in microseconds. Instead of just converting, this
patch tries to be a bit more future proof and embed the unit into the
type - and we then default to microseconds.
I have verified that the JMX measures now report sane values for both
the storage proxy and the column family. nodetool cfhistograms still
works fine. That one is reported in nanoseconds, but through the
estimated_histogram, not ihistogram.
Fixes#1836
Signed-off-by: Glauber Costa <glauber@scylladb.com>
608d825790