Use the shiny new Sholl Analysis version

This is one of the many steps in the direction of reproducible Fiji
builds (i.e. having only defined release versions as dependencies).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #67 from fiji/sholl-analysis-3.4.0

Use the shiny new Sholl Analysis version
write-headless-jar: adjust to current headless support

The headless support migrated to ImageJ2 for better maintaining and
more robust unit testing. The way the headless.jar can be written
changed, too...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Make './Build.sh misc/headless.jar' work again

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