As Jesse mentioned in one of his emails we need to break up the IDESettings
to smaller parts in order to put them into various core modules.

Jesse wrote:
I meant that if we move IDESettings out of the "real" core, which we should, it 
would need to be broken up. MDI vs. SDI in core/windows. Show File Extensions in 
core/ide. Show Tips of the Day in core/ui. Etc. Even using packages.txt there is
no way to easily split up stored SystemOption settings.

Jesse also wrote:
So we would need to provide something which can quietly load old stored 
IDESettings instances - and either ignore them (make users do it again) or apply 
each property to the new submodules. Tricky.

Hopefuly this can be done as part of the switching to new format of settings.