Remove ugly empty rectangle in empty active teams list for real

Fix simple team hats (32×64) not tinting correctly while on rope or using blowtorch

Remove “Upload to YouTube” functionality which has been broken for years

Various minor frontend CSS tweaks - Static border color for stats, teams list, map draw widget - Explicit definition of table header - New splitter design which works with the Qt style “Windows”

QTfrontend: Remove ugly rectangle in list of active teams when there are no teams

- Hide 'Campaign' button (not ready on iOS...)

Frontend: Properly “gray out” most disabled widgets (a lot of them weren't)

Some padding tweaks in options and team editor pages. Fixes insane width of context menu of hog name line edit

Make video metadata strings translatable in frontend In the video page, a small part of the strings was untranslatable, e.g. “Player: ”. These were part of the video metadata. Now these are localizable.

- Fix archiving (?)

- Pause game when it goes background (do not show anymore annoying 'confirm quit')

- Do not delete Beach theme (it's official one now)

Drop Qt XML from dependencies. QXmlStreamReader is part of QtCore

Remove Qt SVG and Qt OpenGL as hard dependencies Qt SVG is not used in the frontend (no SVGs are rendered). Neither is Qt OpenGL used. Qt OpenGL is discouraged anyway.