Fix Ctrl-S Predicate

[Brent Long]

Ctrl-S conflicts with Ctrl-Shift-S because Ctrl-S does not define shift as false. Needs to be updated with false shift.

Something like this:

CTRL_S: function({ ctrlKey, metaKey, keyCode, shiftKey }){
        return ((ctrlKey === true || metaKey === true) && shiftKey === false && keyCode === 83);
}

[Blaine Bublitz]

Assigning to @urbantumbleweed