replace console warn/error with alert for devices where console is not easily accessible

console-to-alert.js

console.oldwarn = console.warn;
console.warn = (...args) => {
    alert([...args].join(' '));
    console.oldwarn.call(null,...args);
}
console.olderror = console.error;
console.error = (...args) => {
    alert([...args].join(' '));
    console.olderror.call(null,...args);
}