JDK 11: Remove JavaDoc Links

[Nikos410]

Hello @mjiderhamn,

since the first PR I've opened for Java 11 compatibility (#87) looks really cluttered, with multiple commits to the same file that sometimes revert each other, I'm splitting the changes into smaller PRs.

Here, I've removed the links to some packages in some JavaDoc comments, because these packages cannot be accessed directly anymore in with Java 11.

[mjiderhamn]

Hi @Nikos410 . Is there a problem with the build (or other tooling) if the packages can no longer be accessed?
Or is this something more aesthetic from your point of view?

[Nikos410]

Hi, thanks for your reply!

With the links in place, some tests error with the message "Missing code implementation in the compiler" when I run them locally in Eclipse or with mvn test. This does not seem to affect the Travis builds, however.

So I guess it is not neccessary to change this, since I could just remove the links when developing locally and put them back in place before committing - This is probably a matter of opinion, if it is better to have the links in place to conveniently browse the documentation but having to go through this additional step every time.

[ArloL]

It works on Travis because JavaDoc is never built there since the build is called like this

./mvnw install -DskipTests=true -Dmaven.javadoc.skip=true -B -V
./mvnw test -B

as explained in Travis Java Documentation.