D26859: Implement the tablet wayland protocol in kwin

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

REVISION SUMMARY
  Uses the tablet classes introduced in kwayland.
  Depends on D26858 <https://phabricator.kde.org/D26858>

TEST PLAN
  Scratched my tablet with a magic stick and it did things depending on the pressure.
  https://youtu.be/GGx0TlNJlzs

REPOSITORY
  R108 KWin

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D26859

AFFECTED FILES
  autotests/libinput/mock_libinput.cpp
  autotests/libinput/mock_libinput.h
  debug_console.cpp
  debug_console.h
  input.cpp
  input.h
  input_event.cpp
  input_event.h
  input_event_spy.cpp
  input_event_spy.h
  libinput/connection.cpp
  libinput/connection.h
  libinput/device.cpp
  libinput/device.h
  libinput/events.h
  modifier_only_shortcuts.cpp
  tablet_input.cpp
  tablet_input.h
  wayland_server.cpp
  wayland_server.h

To: apol, #kwin, #plasma
Cc: kwin, Orage, LeGast00n, The-Feren-OS-Dev, 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