starting with some basics

The provided test file (test_satie.scd) shows some existing functionality. Not much yet. In order for the file to work you will want to copy audiosources/, effects/, mappers/ and spatializers/ from the "official" SATIE repository. I was going to include them here but didn't want to clutter the MR. I can do it, though, for the completness' sake. So go ahead, comment, suggest, conquer.