Merge topic 'ep-REBASE_CHECKOUT-fallback'

dec997f04e ExternalProject: Remove extra quotes in for-each-ref update step
704e87ee8c Help: Clarify behavior of REBASE_CHECKOUT when switching branches

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !7011