Make the code compile on Java 10+

[ggam]

At the moment the project doesn't compile with Java 10. Since the build system is still being cleaned up, drastically simplifying it, this is a reminder that at some point this task will need to be accomplished.

[arjantijms]

By the time we'll get to this, it's probably going to be JDK 11.

[ggam]

Yes, we are in a hurry if we want to make this before Java 11 http://www.java-countdown.xyz/
But hopefully fixing it for Java 10 will still work on the next versions.

[ggam]

Interestingly, Java 11 goes beyond 10 compiling Mojarra. With Java 10 I was getting a "static import only from classes and interfaces" error that might actually be a JDK bug, but with 11 that's gone and the first fail is compiling a test with error:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-ear-plugin:2.10:ear (default-ear) on project correctScanningEar: Execution default-ear of goal org.apache.maven.plugins:maven-ear-plugin:2.10:ear failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-ear-plugin:2.10:ear: java.lang.ExceptionInInitializerError: null

Maybe updating Maven dependencies does the trick.

[lasombra]

I got it working locally with this PR. Hope it's enough to close this issue. :)