Also added missing logic to GraphExplorerComposite.SelectionElement to
discover Resource from Variable when WorkbenchSelectionElement is asked
for AnyResource. This is part of the fix for #7116.
Fixed breakage from ContextualHelp F1 keystroke handler which was
introduced in the original SVN commit r32734 (#6446).
refs #7116
refs #7117
Change-Id: Ia7c88d2c1b274fd788a0a18d95c2f059cea36086
(cherry picked from commit
e84008c029ef2336cf55ad371256c9a12a889e98)