Camera: ISO C++11 build fixes

Fix build in ISO C++11 mode:
- enum typesafety
- constexpr

Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
camera: updated german translation

Patchset 1: initial update
Patchset 2: fixed typos, added non-translatable flag for one default string
Patchset 3: rebase, fixed typos, added missing translations
Patchset 4: fixed missing upload
Patchset 5: more typo and wording fixes
Patchset 6: rebased
Patchset 7: added strings from commit Ib2c2c152; fixed some wordings
Patchset 8: fixed some wordings
Patchset 9: rebased
Patchset 10: fixed two wordings
Patchset 11: fixed one typo

Change-Id: Ie8fe89e6d6bca4399302c6370d324b9bc703e2d4