Add setting to use preset api key for LocalAdministrator.

Move logic from UsersController to UserStore.
Allow roles to be aliased to other roles in roleMapping config section.
Add routes and handlers to redirect NuGet client.

Allows deployments to point Visual Studio or NuGet to the root path and
have it redirect to the right place for OData, pushing and deleting packages.
Make NuGet.Lucene.Web depend on same version of NuGet.Lucene.
Minor version bump.
Handle runtime exceptions thrown by package origin when attempting to mirror packages.
Avoid sending too much traffic to origin when mirroring packages.

 - Cache results for 5 minutes
 - Don't look in origin for packages that are local
Merge remote-tracking branch 'upstream/master'