Feature/master/sqlgen

Updates the annotation-driven SQL-generating code under src/java5 from a while back to remove the dependency on org.objectweb.asm and instead use the annotation processing now built into javac as of Java 6. New annotations for including arbitrary SQL commands to go along with autogenerated function and trigger declarations. As discussed on pljava-dev.

After thinking of a few possible organizations, I ultimately moved both the annotation interfaces and the annotation processor into pljava-api. That way user code can be compiled with nothing more than pljava-api.jar on the classpath and everything works including descriptor generation, and nothing was complicated in the maven setup.