Chris Muller uploaded a new version of Traits to project Squeak 4.5:
http://source.squeak.org/squeak45/Traits-topa.302.mcz

==================== Summary ====================

Name: Traits-topa.302
Author: topa
Time: 25 January 2014, 11:54:10.589 pm
UUID: 58712f55-3f3f-467e-ac0e-e118c9737c53
Ancestors: Traits-cwp.301

Move trait-backstops back to Kernel, so trait unloading still works.

=============== Diff against Traits-cwp.301 ===============

Item was removed:
- ----- Method: Behavior>>allTraits (in category '*Traits-Kernel') -----
- allTraits
- 	"Backstop. When traits are unloaded there are no traits hiding here."
- 	^#()!

Item was removed:
- ----- Method: Behavior>>hasTraitComposition (in category '*Traits-Kernel') -----
- hasTraitComposition
- 	"Backstop. When traits are unloaded we never have a trait composition"
- 	^false!

Item was removed:
- ----- Method: Behavior>>traitComposition (in category '*Traits-Kernel') -----
- traitComposition
- 	"Backstop. When traits are unloaded we never have a trait composition"
- 	^#()!

Item was removed:
- ----- Method: Behavior>>traitCompositionString (in category '*Traits-Kernel') -----
- traitCompositionString
- 	"Backstop. Monticello needs a traitCompositionString even with traits unloaded"
- 	^'{}'!