Merge with proxmox upstream, don't bump package version.
Backport stable zram patches up to 3.18

Patch series are pulled from: https://github.com/ffzg/rhel-3.10-zram
We also include initial lz4 support, only tested on zram.
Merge pull request #9 from ffzg/zram-backport

Zram backport, merge with upstream.