DefaultTranslator creates ImageMetadata

When the DefaultTranslator is invoked it now ensures an appropriate
number of ImageMetadata are created.
Added JPEG2000 SCIFIO format

Converted the loci.formats JPEG2000Reader, Writer and MetadataParser to
and ome.scifio Format.

Converted supporting codec classes as well.
Added JPEG SCIFIO Format

Converted the loci.formats JPEGWriter and JPEGReader to a single
ome.scifio JPEGFormat.

As the loci.formats JPEGReader/Writer used the ImageIO API, a general
ImageIOFormat was also created (which components of JPEGFormat extend).

Also, the loci.formats JPEGReader used a delegate between ImageIO and a
TileJPEG implementation. These have been split out to separate formats
in SCIFIO.
Converted NRRDFormat to SCIFIO

Converted the loci.formats NRRDReader to an ome.scifio NRRDFormat.