BUG #14705: Add ability to hide time marker.

Added mechanism to plot views that can show time-markers (such as
line-chart, bar-chart) to hide the time marker. There's a new property
now available "Hide Time Marker" (it's an advanced property) that one
can check to no longer see this marker. This property is accessible from
the "Properties" panel (under the View section).

Change-Id: Id71028b188b4adde68ad0b6b06fba142832b0ec2
Merge topic '14705_hide_time_marker' into next

24a4ee06 BUG #14705: Add ability to hide time marker.