[release] pom changes for 1.8-SNAPSHOT

* Enforce maven 3.2.1 at least.  No reason to say on the old when the
old isn't used.  Version 3.2.1 is being shipped with eclipse 4.4
versions.  It isn't quite the latest but allowed good fallback.  Maven
is discussing getting here soon as a base.
* Removed temporary comments for multi module build
* Ensure 1.8-SNAPSHOT marked everywhere.  No point is trying to be smart
here as maven release will just change values later so noting version
directly.
* Add url on all projects as there is only one site and not noting it
causes it to list incorrect site by project level.
* Make properties out of more versions
* switch jetty to use latest ecj
* updated jgit and plexus utils