Lyude Paul authored Nov 21, 2016 and Chris Wilson committed Nov 29, 2016

Since we're going to be using lists for keeping track of EDIDs we've
allocated on the chamelium, add some generic list helpers from the
wayland project.

Signed-off-by: Lyude <lyude@redhat.com>

Changes since v1:
- Rename list helpers to be more like those from the Linux kernel

v2: Make the api compatible with the kernel as well.