Initial CellH5 Reader class

Hi there,

this is the cellh5 reader for bioformats. It implements basic viewing of the raw data contained in the cellh5 hdf5 files. I hope I am on the right track and comments are more than welcome (I am a java noob) 

For future versions of the reader, I want to implement:

* multiple series
* more MetaData Tags (e.g. Timestamps)
* export of segmentations as OME-ROI (hint regarding that are also very welcome :))

Cheers,
Christoph