[PVE-User] pve-kernel repository: merge of 4.15 branch into master

[Thomas Lamprecht]

Hi all!

We branched out the old master into a pve-kernel-4.13 branch and merged the
the pve-kernel-4.15 branch into master.

New development/updates for the kernel will now happen in master only,
but I'll try to have the pve-kernel-4.15 branch in sync.

We will now try harder to branch out stable releases and keep the newest
release (or future development) on the master branch, e.g. if we'd start
working on a new kernel release for Proxmox VE 6 in this repository.

Anyway, for those people who build their own kernel, please fetch the new
changes and switch to the respective changed branch.

cheers,
Thomas