Implement dynamic, pattern-matched keybindings

[steveluscher]

It would be great to be able to define keybindings that match patterns, such as:

key('⌘+([0-9])', function(e, handler) { … });

or

key('⌘+(\d)', function(e, handler) { … });

or

key('⌘+shift+(.*)+(.*)', function(e, handler) { … });

…where handler.matches is an array containing the key(s) that matched the pattern(s).