Colours in user defaults

[Germán Arias]

After update base and gui there is a problems when store colours in user
defaults. Gemas.app store the colours with something like: 

[defaults setObject: [NSKeyedArchiver archivedDataWithRootObject: color]
             forKey: @"EditorInsertionPointColor"];

but then the Gemas.plist become unusable and can't be used the next
time. But this worked fine some days ago.

Germán