Mutations Needle Plot v0.7.0

A needle-plot (aka stem-plot or lollipop-plot) plots each data point as a big dot and adds a vertical line that makes it appear like a needle.

Changelog:
v0.7.0
 * Regions format changed (new)
 * Repeated regions labels stacked (one visible)
 * Legend placement fix
 * Coordinates tip disappears in time.