Source and test reorganization and Groovy core / gdk artifacts

The Groovy artifacts should be split in two:

• a groovy-core.jar containing what's core to the language and the JDK (closures, default groovy methods, Swing builder, etc... with the addition of GroovyTestCase)
• a groovy-gdk.jar containing all the library related stuff (JMX, etc)

The groovy-core.jar should be "JarJar-ed" to embed ASM and Antlr.
The ASM and Antlr classes embedded should be kept to a minimum (removing non-needed things like Antlr's python support and the likes)

The sources and tests should be seperated accordingly in two different tree structures.
No dependency from groovy-core on groovy-jdk, but groovy-jdk obviously depends on groovy-core

Current tests should be put in some final10 folder (a better name might be appreciated) to keep all the tests as a regression testing process.
New tests should have their own folder (package).
And a dedicated package for TCK (language-related) tests should be created.