Plasma, ARGB and 4.5

[Marco Martin]

Hi all,
right now plasma enables argb visuals with that magin X11 code pasted in many 
places...
since 4.5 now can handle it
by setting Qt::WA_TranslucentBackground on the top level window we want 
transparent we can make it in a prettier way

and since there seems to be some problems lately, like invisible panels i want 
to use it asap, that would eliminate a possible cause to that problem
that would also mean that we will depend from 4.5 from that exact moment since 
that flag is not present in 4.4, so i want to ckeck with you all :D

if it's ok, i'll start to eradicate that piece of code and set that flag on 
all toplevel windows we're interested
all the views (directly in plasma::view or just in ones we really want 
transparent, like panelview and dashboardview?)
dialogs, tooltips and so on...
i'm currently playing with it and what i found is this:

it seems to reset window flags, so must be applied before saying for instance 
that this window is frameless or a dock (will try to make a small test case to 
see if it's a qt bug)

junk again in kde4 systemmtray icons :p

apart from that doesn't seem to cause other problems, didn't have the 
invisible panel issue, dunno if it fixes it or if i'm luvky :p

Cheers,
Marco MArtin