Additional fix for issue 2965.

CacheStat returns tristate (succeeded/failed/unknown), not bool, so
tweak return values yet again.
(cherry picked from commit 95ea4f698a385f7f8e6158ef60b058cac123cffc)
Temporary templating bundle should be placed in default namespace.

Add acceptance test. Close #2928
(cherry picked from commit df6afa46d072d05dc1e7ce31c3ebf2bb189745f3)
Merge remote-tracking branch 'upstream/3.5.x' into 3.5_surfsara