preload popups of some applets after init in the background
based on a value of X-Plasma-PreloadWeight in the desktop file
if present, otherwise some default values based on the applet
type (Provides)
Save the weight in the config, if an applet is never opened,
slowly decrease the weight, when it reaches 0 don't preload it
next start, increase every time it gets opened, so at the moment
it's quite aggressive about preloading, in order to not do it
a lot of plasma startups without touching the applet are needed
Applet with a very big weigth will be preloaded immediately,
therefore having an impact on the time it will take to have
a panel visible and usable, while lesser weigths will preload
after a random number of seconds between 2 and 10, so will load
in the background after everything is started