D12233: Avoid manipulation of lists with quadratic complexity

[Luca Beltrame]

lbeltrame added a reviewer: mgallien.

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D12233

To: bruns, #baloo, michaelh, mgallien
Cc: dhaumann, ngraham, kde-frameworks-devel, jtamate, bruns, ashaposhnikov, 
michaelh, astippich, spoorun, abrahams