Allow for bookmark names to be passed in via key binding

Hi,

A small change which allows me to bind keys to specific named bookmarks (e.g. Alt-0 .. Alt-9) to mimic functionality I'm used to in SlickEdit. If no name argument is passed in, it uses the old behaviour of using the currently selected text, else it uses the name.

I had some confusion on an earlier pull request which added quick bookmarks and which had code changes in the same area? I'm new to git, to I *think* I based this on the most current version...