Instead of copying classes to the compile output, we now add them directly to the JAR.
This allows JavaCompile to be cached, since there are no overlapping outputs anymore.
As of Spring 4.3 RC1 the `org.aopalliance` interfaces are once again bundled
with `spring-aop` [1]. Moreover, all modules with a dependency on
`aopalliance:aopalliance` directly or indirectly also depend on `spring-aop`.
This change drops the `aopalliance:aopalliance` dependency in all places it's
declared. Where applicable an explicit dependency on `spring-aop` was added in
its place. (This dependency was already present in most places; in one case the
module didn't require `aopalliance:aopalliance` in the first place.)
The documentation is updated accordingly.
[1] https://jira.spring.io/browse/SPR-13984
