Bug fix: do not run tests twice on java8

Previously, on java8, tests were sometimes executed twice, because HavaRunner relied on bug on Java7

See http://mail.openjdk.java.net/pipermail/jdk8-dev/2014-January/003955.html and https://bugs.openjdk.java.net/browse/JDK-6695379

This fixes it by only running non-bridge test methods.

There are some cleanups to do, so not ready for merge yet, but comments are appreciated!