POM: bump to pom-imagej 5.0

This restructures the parent POM dependency management,
and inherits the latest dependency versions.
POM: tidy up configuration blocks

Accomplished using:
    mvn tidy:pom
POM: upgrade to latest version of jersey

Unfortunately, version 2.0 seems to have a missing dependency:

[WARNING] Could not find artifact org.eclipse.persistence:org.eclipse.persistence.antlr:jar:2.5.0-M13 in imagej.public (http://maven.imagej.net/content/groups/public)
...
Path to dependency:
	1) net.imagej:imagej-server:jar:0.1.0-SNAPSHOT
	2) org.glassfish.jersey.media:jersey-media-moxy:jar:2.0
	3) org.eclipse.persistence:org.eclipse.persistence.moxy:jar:2.5.0-M13

Version 2.13 works, but some artifacts were built to require Java 7,
so this change also updates imagej-server to require Java 7 now.

There is still a failing unit test.