add support for multi-phase processing and processor orchestration

Hi everyone,

i'v started writing a transcoder using spoon and I'v based my code on the Launcher example which uses a Factory/ProcessingManager (see below) which then sends CtClass and CtInterface instances to two AbstractProcessors. My question is around the best way to approach multi-phase processing. I can happily extract all the class information from CtClass/CtInterface but I find I'm going to need to scan source tree twice. Scan one to do analysis and the second scan when I generate the output.

I guess my question is what the recommended approach for this is. If I simply keep my own references to all the CtClass/CtInterface instances could this cause memory issues, having all nodes is loaded in memory. Does the processor throw away each class as it moves to the next?

Or, do I just run two of these?

```
final String[] args = { "--input", path, "--output-type", "nooutput" };
launcher.setArgs(args);
launcher.run();

runProcessingManager();
runProcessingManager();
}

private void runProcessingManager() {
Factory factory = launcher.getFactory();
ProcessingManager processingManager = new QueueProcessingManager(factory);
processingManager.addProcessor(new ClassProcessor());
processingManager.addProcessor(new InterfaceProcessor());
processingManager.process(factory.Class().getAll());
}
```