Allow the user to interact with link anchors in the qtconsole Since the qtconsole can display hyperlinks, it would be useful to allow interacting with them. This adds showing a tooltip when the mouse is over a link. The tooltip code stores the anchor in ConsoleWidget._anchor, so when the user right-clicks to select the context menu for "Open Link" or "Copy Link Address", it uses the text that was displayed and not whats under the current context menu pointer location. Also storing the anchor allows me to check to see if we've already displayed that anchor on a new mouseMoveEvent so the tooltip doesn't keep getting redrawn.