Capitalization of titles, labels and other user-visible strings

Created by: das-g

@sfkeller noted we use inconsistent capitalization and proposes:

• Use title case (all words capitalized, except for 'small' words like "of") for navigation buttons at the top and top page titles (<h2> near the top of the white area below the blue navigation bar)
• Use sentence case (first word and proper nouns capitalized) everywhere else ** exception: status display ("available until", "started at", "finished at" etc.) may remain all-lower-case

Don't forget:

• Detail level "Full detail"
• "(Rough) estimated file size"