bf-imagej.sh: also update Bio-Formats jai_imageio

SCIFIO uses a repackaged version of jai_imageio, but the name still
clashes with the Bio-Formats version (whose fork was *not* repackaged).
To avoid the clash, we now do the same thing as with the two "scifio"
artifacts: the io.scif version lives in jars/ and the Bio-Formats one
lives in jars/bio-formats/.
Stop hard-coding the imagej-maven-plugin version

In our pom.xml, we configure the imagej-maven-plugin, but since we updated
to a current pom-scijava parent, we no longer need to specify the version
explicitly.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Bump to pom-scijava 1.78

Signed-off-by: Jenkins <jenkins@dev.loci.wisc.edu>