21 - more jdk9 improvments

• new version of plugins that ootb work on jdk9, our plexus-archiver override no longer needed for them
• newer version of plexus-archiver & addition of plexus-io override to make sure it always works correctly
• removal of eclipse plugin as it was no longer maintained and it is replaced by native support in eclipse.
• removal of intellij idea plugin as it is no longer needed. IDEA handles maven really well.
• maven minimum requirement was lifted to 3.2.5, but can be overridden by projects themselfs.