javac: ignore `@jdk.Profile+Annotation` as generated by Java 8 #1347
AbstractTransformer: sort the local declarations to get the same results on Java 7 and 8 #1347
model loader: correctly mark defaulted interface methods as such in Ceylon model #1616

This allows us to not generate a method for them in Ceylon or Java subtypes of Java interfaces with default
methods. It does not allow us to invoke them with super.
Model loader #1347: Use JDKUtils to figure out the current version of the JDK
Module manager #1347: if we ask for JDK7 on JDK8, substitute it for JDK8
Test for #1347: Investigate if we work on Java 8

Added a new test/java8 folder which contains Java code to compile with Java 8, and
its compiled version to git too. The test is only run when on Java 8, though