>= saucy on kernel 3.4 and non-Atom Intel, downgrade mesa to version 8 (precise)

Discussed extensively in #704.

The tricky part is that `libegl1-mesa-drivers` was split in 2 parts, so there is a new `libwayland-egl1` package (required by kde). We create a fake package with `equivs` to work around that.

Tested in `2014-07-06_10-19-56_drinkcat_chroagh_x11test.tmp-pin-3.4-drivers_-R_precise-saucy-trusty_35`, output is here:
http://drinkcat.github.io/chroagh/2014-07-06_10-19-56_drinkcat_chroagh_x11test.tmp-pin-3.4-drivers_-R_precise-saucy-trusty_35.html
(3D acceleration is working on all platforms and Ubuntu releases)

@DennisLfromGA, @peter-gulka: Could you test this branch? In particular, I'm interested in KDE and Steam (testing Gnome, Unity, XFCE would be good too).
You can fetch the branch here: https://github.com/drinkcat/chroagh/archive/pin-3.4-drivers.zip, then extract and run `sudo sh installer/main.sh -n chrootname -u`
We dist-upgrade in core; is there a reason we need to do it here as well?