Fixed crashbug in OnJobCallback in PlexDirectory.
Fix carshbug where we couldn't get the filterbutton.
Most likely fix a crash in std::vector::insert

c.f.
https://www.bugsense.com/dashboard/project/8a865bdb/errors/344038034
Guard against no timelineManager in Search.
Guard against not finding a editControl in search window.
Guard in ServerManager.
Fix potential crash in GUIListGroup

C.f.
https://www.bugsense.com/dashboard/project/8a865bdb/errors/302598084
Fix items lost in the home menu.

Fixes #830
Sign the updater as well.

Fixes #829
Sort filtervalues correctly.

Fixes #711
Fix loading of filters from remote servers

Fixes #832
Add letter scroll offset indicator. Fixes plexinc/plex#754
Fix Volume & Mute dialogs. Fixes plexinc/plex#833
Don't show spoiler alert if item has no plot. Fixes plexinc/plex#834
Change filtered episodes thumbs to fanart and other small tweaks.

Because Elan :)
Create a new default smaller Posters view, and make the previous one optional.

Because Elan, again.
A transparent dark background for Overlay icons (better visibility), and a ton of tiny pixel shifts in positionings.
Create a Preference for hiding Unwatched/InProgress indicators in library views.
Fix Overlay icon position in Clips view.
Make selected Photo border consistent with other views.