[Shotwell] strings inconsistencies and notes

[Alexandre Franke]

Minor detail that you can add to this list:
for strings that have plural forms, in the singular form, sometimes
you use %d, sometimes you use 1. It's not a serious issue but it's
inconsistent.

Another detail: there are many occurences of "photo" and only one of
"Picture" which you might want to change to photo.

-- 
Alexandre Franke