Do we want to rebrand GUI so builds are obviously unofficial by default?

[reticulatedpines]

We've had some discussion on this previously - should we change the build process so ML builds are, by default, obviously not official release builds? Probably some change to GUI on all screens so it's branded as unofficial.

Pros:

• simplifies support process
• encourages forks to get features added upstream

Cons:

• requires work
• might be considered unfriendly?

Quite a few open-source projects do something like this (e.g. Firefox), often by having a logo for official builds that is licensed in a less permissive manner, and using that for official branding. Unofficial builds don't have permission to use that brand or name.