[Preview] Upcoming changes for Jena 4.3.0

[Andy Seaborne <an...@apache.org>]

For the next Jena release, there is a change to use JDK java.net.http 
package for HTTP. This affects authentication.

There is also a lot of code cleanup around SPARQL operations.

Fuseki users are not affected by these changes.


* HTTP usage provided by the JDK java.net.http package, with 
challenge-based authentication provided on top by Jena.

* Execution objects (QueryExecution, UpdateExecution, RDFConnection) 
have a companion builders for detailed configuration.

This is especially important for HTTP as there many configuration 
options that may be needed (including template queries).

Local use is still covered by the existing QueryExecutionFactory as well 
as the new QueryExecutionBuilder. Some remote create operations in 
QueryExecutionFactory which exposed Apache HttpClient object has been 
removed.

* HTTP/2 support (comes from using java.net.http package)

As well, there is a lot of clearup:
See notes on changes:

https://jena.apache.org/documentation/sparql-apis/#changes

Please test the development builds and provide comments.

     Andy