Add Base64 Encoding helper

This will be used when creating temp actor names
Make Address IEquatable<Address> and add equality operators
Add ActorPath: Root, Parent, == and != operators. Make Elements an IReadOnlyCollection

Making Elements an IReadOnlyCollection makes checking for empty paths so much easier.
Include full exception when logging errors.

Useful information was missing, such as inner exception info.
Props should, when failing to create actors, have better error message
Fix spelling error in RoutingSpec
Rename files in examples
Merge pull request #159 from HCanber/minor-things