Use primary Jenkins URL

It already defaults to the ImageJ view anyway.
Remove obsolete imagej-maven-plugin Eclipse config

The set-rootdir goal moved to the scijava-maven-plugin.

And anyway, it is bad to have lifecycle-mapping configuration outside of
a profile triggered by the use of M2E; see:
http://stackoverflow.com/a/23707050/1207769
Reintegrate version management into pom-imagej

This unifies the Bill of Materials (i.e., dependency management) for all
artifacts in the net.imagej, net.imglib2 & io.scif groupIds (i.e., the
imagej, imglib & scifio GitHub orgs, respectively) back into one place.

The pom-imglib2 and pom-scifio parents will now extend pom-imagej to
inherit the complete Bill of Materials.

For the discussion and rationale relating to this change, see:
http://imagej.net/pipermail/imagej-devel/2014-October/002280.html
Merge branch 'imagej-is-da-bom'

For discussion and rationale, see:
http://imagej.net/pipermail/imagej-devel/2014-October/002280.html