Add support for maven 3.2

* Changed maven version to 3.2.2
* Remove enforcer rule for maven version 3.0.5
* Replace aether sonatype with eclipse (https://github.com/evgeny-goldin/maven-plugins/issues/10)
* Replace sonatype aether packages in src code with the eclipse packages
* Change enforcer plugin to version 1.3 to be compatible with mave 3.2 (https://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound)

Note: Silencer plugin is not configured to run while building the maven
plugins anymore, since previous version of the plugin is not compatible
with the new one.