D27174: actually draw drag icons in the mouse cursor during drags

mart created this revision.
mart added reviewers: Plasma, KWin.
Herald added a project: KWin.
Herald added a subscriber: kwin.
mart requested review of this revision.

REVISION SUMMARY
  paint together the cursor image and the extra dnd image if available
  on X11 with QDrag::setHotspot is possible to control their relative
  position, which doesn't seem to have a wayland protocol correspondence
  so their relative position are controlled just by the hotspot of the cursor itself

REPOSITORY
  R108 KWin

BRANCH
  phab/dragicon

REVISION DETAIL
  https://phabricator.kde.org/D27174

AFFECTED FILES
  pointer_input.cpp

To: mart, #plasma, #kwin
Cc: kwin, Orage, LeGast00n, The-Feren-OS-Dev, cblack, jraleigh, zachus, fbampaloukas, GB_2, mkulinski, ragreen, jackyalcine, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, ahiemstra, mart