Configuration changes

[Moonchild]

Recent changes in the tree's default configuration should be noted for people maintaining their own builds for e.g. distros.

• Gamepad support is now disabled by default for all UXP applications. If you need gamepad support, enable it in .mozconfig with "ac_add_options --enable-gamepad"
• The internal updater and mar packaging support is now disabled by default. If you need the internal updater, enable it in .mozconfig with "ac_add_options --enable-updater"

[JustOff]

Perhaps "ac_add_options --enable-av1" is also worth to be mentioned?

[Moonchild]

No, it is not.

I wanted to focus here on defaults that have changed and that are important for existing builds. Experimental features that are currently behind a build flag are hardly of the same magnitude of importance.