idr0012: Add roi import plugin

[dominikl]

CLI plugin to import the ROIs from the hdf5 file created by #289 .
Doesn't work yet, because there are 4 fields / well in the data, but only 2 fields / well in OMERO!
See my comment on https://trello.com/c/hjEUogsi/23-rois-idr0012-fuchs

[joshmoore]

Finally got a chance to compare this and gh-287. We may need to discuss the naming collision here: there won't be a way to activate both of the plugins at the same time. Perhaps that's ok, since you'll only ever be running one at a time, but there would be no way to have them, e.g., all on the PYTHONPATH at the same time. This makes me think of a RoiReader and whether or not we should detect these "formats" at runtime.

[dominikl]

That's true. I.e. have only one roiimport command (still looking for a better name btw) and specify format via an extra argument --format=idr0012, --format=idr0016, etc. ?

[joshmoore]

Something like that, yes. It might be that as with readers.txt from Bio-Formats, we can specify the (Python) class name for --format in addition to some well-known formats (cellprofiler, etc)

[dominikl]

Replaced by #292