[Autofac, ServiceLocator cleanup] Removed old GAC scanning util backport that was need when in Dynamite for SP2010 (old Autofac version didn't have assembly scanning utils).
- Split ServiceLocator namespace's types into a few sub-namespaces: Internal (for hidden stuff), Lifetime (for instance-per-web/per-site/per-request stuff), AddOn (for plugin-framework type architecture stuff).
- InstancePerRequest, InstancePerWeb and InstancePerSite registration extensions are now part of Servicelocator.Lifetime sub-namespace. Might be annoying - we'll see.
- The PerRequesLifetimetHttpModule namespace changed as well. The WSP's WebConfigModifications feature will need to be re-activated to edit all relevant web.configs in your environment.