D17299: move implementation of document get to cpp file

[Alexander Stippich]

astippich added a dependent revision: D17300: add result to baloo namespace.

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D17299

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