Set marker tooltip rather than thing "across the road" tooltip

[mdreid]

When you hover over a marker in Eclipse, you don't see any message. If you instead hover over the right-hand ruler markers, you see the message.

Let's show the message over the marker too.

[mdreid]

This might be useful: http://stackoverflow.com/a/10107110

[mdreid]

Also see: http://help.eclipse.org/mars/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fapi%2Forg%2Feclipse%2Fjface%2Ftext%2Fsource%2FSourceViewerConfiguration.html

http://help.eclipse.org/mars/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Fguide%2Feditors_sourceviewers.htm