Move MethodGroup to the root namespace, since it is a first class domain concept related to Case, which is also in the root namespace.
Move PassResult, FailResult, and SkipResult to the Fixie.Results namespace.
Move GenericArgumentResolver and ObjectExtensions from Fixie.Discovery to Fixie.Internal, since they have nothing to do with discovery and are not meant to be directly useful to end users.
Adjust MethodGroupTests' namespace corresponding with MethodGroup's namespace.
Move built-in behavior classes to the Fixie.Internal.Behaviors namespace.
Move Behavior, BehaviorChain, and BehaviorContext to the Fixie.Internal namespace.
Move Runner to the Fixie.Internal namespace.
Move ClassRunner to the Fixie.Internal namespace.
Update test assertions affected by recent namespace changes.
Move AssertionLibraryFilter to the Fixie.Internal namespace.
Move ExecutionPlan to the Fixie.Internal namespace.
Move all Fixie.Results types into Fixie.Execution, because they are directly involved whenever Fixie.Execution.Listener or Fixie.Execution.ExecutionEnvironment are invovled.
Move Fixie.Discovery classes to the Fixie.Internal namespace.
Move ExecutionProxy to the Fixie.Internal namespace.
Drop unused using declarations.
Merge pull request #69 from plioi/AdjustNamespaces

Adjust namespaces