Merge pull request #219 from Maledictus/master

Blogique: add preview
Fenet: added WM control plugin stubs.
Merge branch 'master' of github.com:0xd34df00d/leechcraft
[Fenet] Added leechcraft-session.
[Fenet] WM finder & sample infos.
[Fenet] Install session scripts with proper permissions.
[Fenet] Added settings.
[Fenet] WMFinder::GetFound{,Model}().
[Fenet] Don't kill lc immediately.
[Fenet] Start the selected WM.
[Fenet] Proper perms for leechcraft-session script.
[Fenet] Added kwin to known WMs.
[Util] Don't segfault if no desktops are known.
[Fenet] Support on-the-fly desktop changing.
[Util] Don't check ShouldShow() in prop notifier.
[KT] Don't complain about unknown windows in updater.
[Vrooby] Enable the filter if no devices are hidden.
[Fenet] Fix segfault on release if WM isn't managed.
[LMP MTPSync] Properly set file size on upload.
[LMP MTPSync] Async polling.