"default" as platform name/definition doesn't tell much and would
only confuse users. "Build-in" is not perfect either but it is
best I've can come with before the release.
Ticket: #3156 (GUI: "default" platform needs proper name)
The iterator was not advanced in the loop. So the code worked when
I ran it in Linux as the first item was matching.
Thanks for Robert for spotting and reporting it.
We have now one list for checked platforms, menu items are created
dynamically based on that list. This makes it much easier to alter
the platforms list later on.