Add DVV to GCounter
Move dotted version vectors into Causaility namespace
Add extension methods for my laziness
Clean up DefaultActorId, Add clone
Add VectorClock
Add FullOuterJoin to extensions
Changed test to compare default to non-default actor
Move default Actor to string
Add IComparable<T> and IEquatable<T>
VectorClock implementation

* Implement `IComparable`
* Implement `IComparable<VectorClock>`
* Implement `IComparer<VectorClock>`
* Add `Merge` to combine vclocks
* Add `Occurs` enum to avoid magic numbers
*
Counter clean up

* Update GCounter with IEquatable<GCounter>
* Update GCounter and PNCounter to use actors instead of DVVPairs