Allow compilation on Java 8

[hermanbanken]

As at the moment many people will have Java 8, we should support Java 8 compilation.

I've compiled Alitheia on both Java 7 and 8 and with the update of FindBugs 0.0.3 and Antlr 3.5.2 it compiles again.

See also antlr/antlr3#151.

[hermanbanken]

While this allows compilation, I still find that Pax Runner does not run on my machine.

I tried to update Pax Runner's <runner>1.5.0</runner> to <runner>1.8.6</runner>, and this works longer, however then I get a PlatformException:

org.ops4j.pax.runner.platform.PlatformException: [link:classpath:runner-links/org.eclipse.equinox.console-1.0.0.link] could not be downloaded

[gewoonrik]

I did the same thing and now it runs for me.

[joostverdoorn]

@hermanbanken did you manage to fix that?