Updating dev NuGet.config
Removing declaration expressions
Fixup references
Activator change requires TypeActivator to be singlton
Merge pull request #81 from aspnet/activator

Activator change requires TypeActivator to be singleton
Startup: Call ConfigureServices if exists
Reacting to Dependency Injection changes
Cleanup headers
Rename UseServices -> UsePerRequestServices
Reacting to CLR package versioning changes
Removing version from framework assemblies node
Update Hosting to account for DataProtection API changes.
Skip failing test due to DataProtection changes.
Add a discriminator so that DataProtection doesn't use the same subkey across apps by default.
Use/EnsureRequestServices changes

- Split UseServices overloads into UseRequestServices and UseServices
- Add RequestServicesContainer class which contains the old
ContainerMiddleware logic and exposes a new
EnsureRequestServices(HttpContext) method which can be called to
populate RequestServices
- ConfigureServices now scans for Configure{Env}Services instead of
ConfigureServices{Env}
- Add OptionsServices as part of default HostingServices
Handle null httpContext.ApplicationServices
Move UseMiddleware from RequestContainer to Http.Extensions.
Support IServiceProvider ConfigureServices()
Change GetService calls to GetRequiredService

GetRequiredService throws for missing services like GetService used to.
Add missing Contracts dependency.