Added v1.4.16 Release notes and updated README

[Aaronontheweb]

1.4.16 February 8th 2021

This is a major update to the Akka.Persistence.Redis plugin.

Enabled Redis Cluster Support
Akka.Persistence.Redis will now automatically detect whether or not you are running in clustered mode via your Redis connection string and will distribute journal entries and snapshots accordingly.

All journal entries and all snapshots for a single entity will all reside inside the same Redis host cost - using Redis' consistent hash distribution tagging scheme.

Significant Performance Improvements
Akka.Persistence.Redis' write throughput was improved significantly in Akka.Persistence.Redis v1.4.16:

Test	Akka.Persistence.Redis v1.4.4 (msg/s)	current PR (msg/s)
Persist	782	772
PersistAll	15019	20275
PersistAsync	9496	13131
PersistAllAsync	32765	44776
PersistGroup10	611	6523
PersistGroup100	8878	12533
PersistGroup200	9598	12214
PersistGroup25	9209	10819
PersistGroup400	9209	11824
PersistGroup50	9506	9704
Recovering	17374	20119
Recovering8	36915	37290
RecoveringFour	22432	20884
RecoveringTwo	22209	21222

These numbers were generated running a single Redis instance inside a Docker container on Docker for Windows - real-world values generated in cloud environments will likely be much higher.

Removed Akka.Persistence.Query Support
In order to achieve support for clustering and improved write performance, we made the descision to drop Akka.Persistence.Query support from Akka.Persistence.Redis at this time - if you wish to learn more about our decision-making process or if you are affected by this change, please comment on this thread here: #126

Other Changes

• Bump Akka.NET to version 1.4.16
• Modernized Akka.NET Serialization calls
• Added benchmarks
• Upgraded to StackExchange.Redis 2.2.11
• Improved documentation