Add support for apostrophes in titles

The href attribute is urlencoded, so (for example) apostrophes appear as
%27. This causes the API request to contain the percent-encoded name
instead of the the actual file name; thus, the API request fails and the
overlay will not work.

To fix this, decode the title from the URL first to get a valid title
representation for the API.

Change-Id: I00f96c9c870b878ca25792a878f3ceb7e9aefacc
Merge "Add support for apostrophes in titles"