Hocon.Configuration 2.0.0

[Add JSON serialization by implementing `ISerializable`.](https://github.com/akkadotnet/HOCON/pull/214) [Resolve `Config` containing a single empty object as an empty `Config`.](https://github.com/akkadotnet/HOCON/pull/214) [Refactor `Hocon.Parser` class to `Hocon.HoconParser` for clarity.](https://github.com/akkadotnet/HOCON/pull/215) [Add `IEquitable<Config>` interface implementation to `Config` class.](https://github.com/akkadotnet/HOCON/pull/218) [Change `GetString()`, `GetStringList()`, `GetInt()`, and `GetDouble()` throws on failure instead of returning a default value to conform to Hocon spec.](https://github.com/akkadotnet/HOCON/pull/218) [Add `TryGet[DataType]()` functions to all getters to eliminate as much Exception throwing as possible to improve performance.](https://github.com/akkadotnet/HOCON/pull/218) [Remove as much wrapping functions as possible to improve performance.](https://github.com/akkadotnet/HOCON/pull/218) [Move `ConfigurationException` from `Akka.Configuration` to `Hocon`](https://github.com/akkadotnet/HOCON/pull/218) [Fix `Config.WithFallback()` with hocon files containing substitution failed to merge the fallbacks correctly..](https://github.com/akkadotnet/HOCON/pull/218) [Hocon is now compatible with Hyperion serializer.](https://github.com/akkadotnet/HOCON/pull/218)