function moveSkippingWhitespace(moveFxn, ctx) {
        if (!moveFxn(ctx)) {
            return false;
        }
        while (!ctx.token.type && !/\S/.test(ctx.token.string)) {
            if (!moveFxn(ctx)) {
                return false;
            }
        }
        return true;
    }
Moves the given context in the given direction, skipping any whitespace it hits.
@param {function} moveFxn the function to move the context
@param {!{editor:!CodeMirror, pos:!{ch:number, line:number}, token:Object}} ctx
@return {boolean} whether the context changed