D26400: Migrate config from KConfig to KConfigXt in order to allow KCM to use it

[Benjamin Port]

bport added reviewers: ervin, crossi, meven, Plasma.

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D26400

To: bport, ervin, crossi, meven, #plasma
Cc: meven, crossi, ervin, kde-frameworks-devel, #baloo, #plasma, hurikhan77, 
lots0logs, LeGast00n, fbampaloukas, GB_2, domson, ashaposhnikov, michaelh, 
astippich, spoorun, ngraham, bruns, abrahams