linux: allow root user to raise priority
[airtunes] - fix - show metadata/coverart on first song aswell by delaying the update to the "OnPlay" event. (before we wouldn't set metadata/coverart because we get it before playback in our player really starts).
[spectrum] Avoid zero height bars that cause display artefacts
[texture] - if FreeResources is called with "immediately" flag set - ensure that this texture is really invalidated - and don't deliver it on the next load from unused texture list
[gui] - don't eat messages in GUIWindowHome but pass them to the base impl.
Merge pull request #3840 from FernetMenta/linux

linux: allow root user to raise priority
videodb: don't show user credentials in source unavailable prompt during library cleaning
Merge pull request #3848 from Memphiz/airtunesanticache

[AirTunes] - fix coverart
Merge pull request #3845 from popcornmix/spectrum_depth

[spectrum] Avoid zero height bars that cause display artefacts