--following plasma approach and use always
even for !compositing mode the widgets/panel-background
svg file. This way when Latte and Plasma panels are
combined there is uniformity between them.
BUG: 406597
--this patch positions correctly behaveAsPanel view
types in !compositing mode concerning and taking into
account maxLength and offset
--the patch introduces also an AppletsContainer to
substitute all three layouts of LayoutsContainer
Michail Vourlakos