Ignore entire ride interval on hover highlight

When hovering over a ride if there is an interval that defines
the entire ride (typical if coming in from WKO+) then don't
hover highlight it, since it is distracting and adds no value.
WKO+ Interval Markers

Rather than skip over the 'standard' interval markers because they
have such verbose names we now plot the vertical marker only.

This is to indicate there is an interval at a particular point to
signpost to the user that they can hover over this point to get an
interval summary.
merge upstream into master