Bump to current Color Inspector 3D version

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Bump fiji-lib to version 2.0.0

This is the first in hopefully a very long line of switches from
SNAPSHOT-version couplings to release ones.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Switch to the new imagej-launcher artifactId

The ImageJ launcher was just renamed from 'ij-launcher' to
'imagej-launcher'.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
download-launchers.sh: fix "release" mode

It now uses only the Sonatype releases repository, so that snapshot
versions are never downloaded when releases are requested.
Build.sh: Fail fast when downloading maven-helper.sh

When downloading maven-helper, sometimes there are network problems.
Rather than storing the HTML error in the maven-helper.sh file, let's
fail fast.

While at it, also download silently.

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