API Improvements and JDK update

[stuartwdouglas]

• Update to JDK 1.8
• Add convenience methods to IndexView
  I don't really know if this should go into a minor because of the JDK update, but this will get rid of a heap of boilerplate in Quarkus where we are wrapping String's in DotName for lookups.

[Ladicek]

The smallrye branch is already updated to Java 1.8, and this will be released as 3.0. It certainly won't go into any 2.x release.

Adding the convenience methods certainly makes sense, but I think it might be even better if we accepted Class objects? From what I saw in Quarkus, that is the most common case.

[stuartwdouglas]

I have added Class versions as well

[Ladicek]

OK I realized that with default methods, this actually requires Java 8 and hence can't go into 2.x. This has to go into 3.0.

[Ladicek]

I rebased on the smallrye branch (which is Jandex 3.0 work in progress) and force-pushed here.