Emulator

Purpose of code changes on this branch:

This patch cleans up the wayland backend and adds the necessary parts to allow dolphin to run as a wayland client.

When reviewing my code changes, please focus on:

I want to make sure that building with wayland egl enabled doesn't affect other platform targets.

After the review, I'll merge this branch into:

If this is good, I will merge it to the master branch.

The patch can be found in the wayland-egl branch here: https://github.com/soreau/dolphin-emu/commits/wayland-egl