MediaLibrary 0.5.0

This is a release aiming at being used by VLC for Android and iOS 3.2.x

It contains many fixes and improvements, including but not limited to:
- Improved support for linking entities together
- Better thumbnail sharing
- Early bookmarks support
- Support for overriding external media with a discovered media
- Better notification support, which won't be held until the last one
  anymore
- Listing banned entrypoints
- Refreshing modified files is now supported
- It is now possible to interrupt the background tasks
- More safety checks for the database models
- Support for multiple thumbnails per media
- Support for thumbnail relocation
- Better playlist support

And many other fixes & improvements.
This release uses the database model v18
This tag has no release notes.