Mavenize.

Moved source code (under src and testsrc) into a maven directory structure (src/main/java, src/test/java, src/main/javacc etc.).

Fixed up build.xml so that ant/subfloor still work. (However, I've not checked that the generated jar and source zip are identical to before.)

Any java files that only compile under jdk5 and jdk6 have been moved to src/main/java5 and src/main/java6. These are currently built under ant but not under mvn. One nice side-effect is that an IDE such as Intellij doesn't find them and fall over trying to compile them. If you're developing & debugging under JDK 1.7, then that's what you want anyway.