Bump to SNAPSHOT version

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Switch to pom-fiji as parent

Our groupId is sc.fiji, after all...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Let pom-imagej manage which ImageJ 1.x version we use

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>