Create cron jobs faster

I've just added new creating form.

With this, you can create your cron jobs faster, with a predefined time interval, e.g every 5, 10, 15, 20, 30 minutes, every 1, 2, 3, 4, 6, 12 hours, etc.

Btw, I added a quota bar. You can hover it to see how many cron jobs are created and allowed.