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This makes it consistent with the analogous comments in
pom-scijava, pom-imagej, pom-imglib2, pom-scifio and pom-fiji.
Improve description

This makes it consistent with the descriptions in other parent POMs,
including pom-scijava, pom-imagej and pom-fiji.
Add a README
Add missing developers section
Update scm section to reflect new GitHub org
Add issueManagement and ciManagement sections
Manage all the components

This adds version management for:

* Descriptor_based_registration
* bigdataviewer-server
* bigdataviewer_fiji
* spim_data

These components need to be managed so that downstream projects can
depend on compatible versions of them.

In particular, the core Fiji project (https://github.com/fiji/fiji)
will depend on most (all?) of them.
Tidy up order of configuration blocks

This was done using:

    mvn tidy:pom
Merge pull request #1 from ctrueden/manage-all

Manage all component versions