move dock/icons size adjustments, to fix window placement
Functions placing windows (PlaceWindow - src/placement.c, wMaximizeWindow -
src/actions.c) need to calculate area differently than ones placing icons
(PlaceIcon - src/placement.c, wArrangeIcons - src/actions.c).
So this patch puts adjustment code in wGetUsableAreaForHead which is
used by all those functions but called with different 'bool noicons'
argument depending on if it's called in window or icon placement
function.
Reported-by: Carlos R. Mafra <crmafra@gmail.com>
Signed-off-by: Amadeusz Sławiński <amade@asmblr.net>