Ensure external Picasso is not null.

- https://crashlytics.com/seriesguide/android/apps/com.battlelancer.seriesguide/issues/53d87dede3de5099ba93891d
- Also modify builder with annotations to create NPE warnings.
Latest translations.

- Exported from crowdin on 2014-07-31.
Push version to 16.0.1, 15022.
Change log for 16.0.1.
Merge branch 'fix-16.0.1'