Improve update

[selfus]

When updating, every time, we need to use the download page, that asks us for a donation, and email (mandatory).

This should be improved for better update process.

[DanWBR]

Only "breaking-change" updates require re-downloading the installer. Normal updates are applied through the automatic updates channel. Donations are optional and emails are only used to inform about the updates themselves. Many people inform a fake email only to get to the download page.

I have no intention to change this, because it is from Gumroad where I get 99% of the donations, which aren't that many, by the way.