JRuby container builder

Here's my start at a container builder using JRuby. No doco yet and there are still improvements to be made, but Paul was asking for it

Have a look at the test cases for an idea of how it works. The basic idea is this – executing a piece of Ruby script always returns the last result. So the last top-level "container" expression is what gets returned to the builder. The parent container and assembly scope arguments are assigned to global variables "$parent" and "$assembly_scope" inside the ruby interpreter.

AFAIK there is no jruby.jar on ibiblio.org yet so to try this you'll have to download the jar attached to the ticket and manually install with:

mvn install:install-file -Dfile=jruby-0.9.0.jar -DgroupId=org.jruby \
-DartifactId=jruby -Dversion=0.9.0 -Dpackaging=jar

I've currently got JRUBY-9 open to get the JRuby guys to either get a binary on releases.codehaus.org or onto ibiblio.