Remove unnecessarily overridden version number
First cut at skeleton implementation

The OMERO-specific bits are not yet filled in; instead, there are
placeholder interfaces marking where some of that logic will go.

The build currently pins to an ImageJ SNAPSHOT; this code will not build
unless you first check out the 'identifiers' branch of the ImageJ2
repository and run 'mvn' to build and install the appropriate SNAPSHOT.

And of course, all of this is completely untested so far...