ISSUE-79: How do we make cmd-+ work?

ISSUE-79: How do we make cmd-+ work?

http://www.w3.org/2005/06/tracker/webapi/issues/79

Raised by: Ian Hickson
On product: DOM 3 Events

Command-= and Command-Shift-= and Command-+ are, or are not, the same key on my
keyboard, and I don't know how to write content that handle Command-Minus and
Command-Plus independent of what the layout actually is, especially given that I
might also want to distinguish Command-= and Command-Shift-= sometimes.