Update references and versions to allow for us to take new FSharp.Core changes

* References in our repository
* Bump assembly version to 4.4.3.0
* Publish new package version with the 4.4.3 assembly

We'll take what we can (if they're ready and make sense) from:

#4020 
#4014 
#3988 
#3691
#4060 
#2534 
#2085 