Automatically determine if filename lengths in the Books directory are limited to 255 UTF-16 characters (NTFS) or 255 UTF-8 bytes (pretty much every other file system) (#1260)
In non-Windows environments, determine if the Books directory supports filenames containing characters which are illegal in Windows environments (<>|:*?). If it doesn't, then ensure those characters are included in the user's ReplacementCharacters settings (#1258).
Use existing BaseUtil.LoadImage delegate, obviating need for derrived classes to load images
Since GridEntry types are no longer generic, interfaces are unnecessary and deleted.
Previously, only some calls to ApiExtended.CreateAsync() would prompt users to login if necessary. Other calls would only work if the account already had a valid identity, and they would throw exceptions otherwise.
Changed ApiExtended so that the UI registers a static ILoginChoiceEager factory delegate that ApiExtended will use in the event that a login is required.
There are multiple subscribers to LibraryCommands.LibrarySizeChanged, and each one calls GetLibrary_Flat_NoTracking(). Passing the full library as an event argument speeds up all operations which happen after the library size changes.
Fix initial backup counts
