D23800: RFC: Use ECMGenerateExportHeader to manage deprecated API better

[Friedrich W. H. Kossebau]

kossebau added a dependency: D23789: WIP: Add ECMGenerateExportHeaders, for 
improved handling of deprecated API.

REPOSITORY
  R244 KCoreAddons

REVISION DETAIL
  https://phabricator.kde.org/D23800

To: kossebau
Cc: kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns