For fully automatic macOS updates, electron-updater requires:
1. Distributing macOS file as .zip (electron-userland/electron-builder#2199)
2. Code signing for the application
privacy.sexy as of today lacks both the distribution and code signing.
This commit introduces auto-updates through automatically checking for
updates, downloading them but requiring user to drag application icons
to Applications by opening dmg file.
This commit also fixes:
1. Progress state in update progress bar not being shown.
2. Downloading updates were being triggered even though it was not
desired as downloads are being handled using different based on OS and
user choice.
In the end it refactors the code for handling updates of two different
kinds, and making message dialog use enums for results instead of
response integers as well as setting default and cancel button behavior.
Refactorings make behaviors more explicit and extends the control.
410bcd8244