As of Spring Framework 5.1, we're depending on the Reactor Californium
release train.
Reactor Netty is now at version 0.8 and changed its artifact
coordinates, package names and broke several APIs. Spring Framework is
now up-to-date with those changes and this commit does the same for
Spring Boot.
Note that in that process, the `NettyServerCustomizer` has been changed
since the former `HttpServerOptions.Builder` API is now gone from
Reactor Netty, and we're now relying on immutable server instances
instead of a stateful builder pattern.
See gh-13321
This commit introduces Kotlin extensions similar to the RestOperations
ones in order to be able to take advantage of Kotlin reified type
parameters for example.
See gh-11039
Move projects to better reflect the way that Spring Boot is released.
The following projects are under `spring-boot-project`:
- `spring-boot`
- `spring-boot-autoconfigure`
- `spring-boot-tools`
- `spring-boot-starters`
- `spring-boot-actuator`
- `spring-boot-actuator-autoconfigure`
- `spring-boot-test`
- `spring-boot-test-autoconfigure`
- `spring-boot-devtools`
- `spring-boot-cli`
- `spring-boot-docs`
See gh-9316
