tracker-extract: Added stub for IVI-compatible MP3 extractor
tracker-info: Added -i switch to support querying the IVI ontology
tracker-miner / tracker-miner-files: Modified to support IVI ontology
Fixed fields in extractor and ontology
Added image properties to IVI ontology
Cleaned MP3-IVI extractor
build scripts: Added enable/disable switches for IVI ontologies and IVI-Mp3 miner
Added PNG-IVI extractor and build-scripts to go with it