o.c.trends.databrowser: Fix NPE when removing item

This error was added with the auto-history-fresh implementation.
o.c.trends.databrowser2: Tab/space cleanup
o.c.trends.databrowser: @inheritDoc to make inherited javadoc more
obvious

.. because that one mentions Model may be null
Merge pull request #562 from ControlSystemStudio/bug560

Data Browser NullPointerException when deleting item
Merge remote-tracking branch 'upstream/master'
fix feature name in core/features/org.csstudio.core.all.feature/.project.

(cherry picked from commit 5368084bbf84019e64cb0fe5738c5789376a0259)
Merge pull request #572 from MichaelRitzert/master

Master
Merge remote-tracking branch 'origin/master' into sns4