Runner: make recentdocument use KActivityStats data
This is a patch moved from https://phabricator.kde.org/D26111 It has one code change : Use of QUrl::AssumeLocalFile And two comments changes.
It is much more versatile over the current recentdocument runner :
- It is activity aware
- It has a longer history
- It includes data from gtk apps
- We will be able to add some quick filtering in krunner
See previous patch https://phabricator.kde.org/D26111