Added Dicom support to SCIFIO

Converted the loci.formats DicomReader to SCIFIO components. See
ome.scifio.formats.DicomFormat. The loci.formats DicomReader has been
converted to a delegator and marked deprecated.

Necessary supporting classes were also migrated:
JPEG2000Codec
PackBitsCodec
JAIIIOService + Impl

These classes will not be converted to delegators until all SCIFIO
formats are converted (at which time they will move to loci-legacy).

As the JAIIIOService classes were moved to SCIFIO, the
MissingJAIIIOService test was also moved to SCIFIO, as the dependency of
scifio on scifio-devel would cause this test to always fail if it
remained.