* Remove the previous method of applying the overlay by flags. In the future the
overlay can just be mounted as a filesystem layer. This is probably how layers
were intended to work in the first place.
* Move the filesystem module info and filesystem name from the fs_mount to the
fs_volume structure. Filesystem layering is done by having multiple layered
volumes and we want to be able to have a different fs per layer.
* Adapt VFS code to this move.
* Implement mounting layered filesystems. Specifying multiple filesystems
separated by a colon on mount will cause the layers to be set up and the
corresponding filesystems to be mounted at that layer.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29199 a95241bf-73f2-0310-859d-f6bbb57e9c96