Merge branch 'akpdw-bug5013-icon-metadata-vanishing' into release-1.16

* akpdw-bug5013-icon-metadata-vanishing:
  (Bug 5013) Add flag to prevent overwriting newly active icons' metadata
Fix "Oops" on journals with deleted themes

Adding 'undef_if_missing' to avoid possibly
breaking other uses of this module.
Merge pull request #442 from anall/hotfix/MissingTheme

Fix "Oops" on journals with deleted themes
Merge branch 'release-1.16' into develop

* release-1.16:
  Fix "Oops" on journals with deleted themes