D27988: KCM/Compositing: Use KConfig XT in UI

meven created this revision.
meven added reviewers: KWin, ervin, crossi, bport, hchain.
Herald added a project: KWin.
Herald added a subscriber: kwin.
meven requested review of this revision.

REVISION SUMMARY
  Use KConfig XT to manage most fields of the KCM.
  Simplify code.

TEST PLAN
  No functionnal change

REPOSITORY
  R108 KWin

BRANCH
  kwin-kconfigxt

REVISION DETAIL
  https://phabricator.kde.org/D27988

AFFECTED FILES
  kcmkwin/kwincompositing/CMakeLists.txt
  kcmkwin/kwincompositing/compositing.cpp
  kcmkwin/kwincompositing/compositing.h
  kcmkwin/kwincompositing/compositing.ui
  kcmkwin/kwincompositing/kwincompositing_setting.kcfg
  kcmkwin/kwincompositing/main.cpp
  kcmkwin/kwinoptions/main.h

To: meven, #kwin, ervin, crossi, bport, hchain
Cc: kwin, Orage, cacarry, 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