Avoid the pesky encoding warning

... as per https://maven.apache.org/general.html#encoding-warning

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Allow to specify deleteOtherVersions via the command-line

When passing the property 'delete.other.versions' via the command-line,
it will override the default (false) and the configuration in the
pom.xml file.

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

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