Stub module for printing metadata.

Basically a slightly modified version of the original training example script,
wrapped into a function for being imported into the IPython shell in OMERO.

Original source:
https://github.com/openmicroscopy/openmicroscopy/blob/develop/examples/Training/python/Metadata.py
Check if there was an actual Dichroic object returned.
Fix the dichroic type check.