Releng: Update Target Platforms and add comments on pom-config

1. Use planner instead of slicer in *.target files
   - This ensures that all dependencies are met for test and dev.
2. Sort *.target files to make them better comparable
3. Align pom-config.xml with TM and fix some download locations
   to better model release streams

Change-Id: I706fcd6eeaed4552c0c0e627e2c754bc800a59b7
Signed-off-by: Martin Oberhuber <mober.at+eclipse@gmail.com>
5 files changed