add some z stuff (FTBFS presently)
add z to some more values
bit more z stuff, don't expect to compile for a while now..
use pragma once instead of header guards everywhere
add glm fixes (definitions to cmake)

add some skeleton logic towards figuring out what z to put things on
compile success, z works..but not for tiles it seems, which are hidden.
try to get z working, needs a rebase against master though
Merge branch 'master' into add-z-pos

Conflicts:
	src/client/FboInSGRenderer.h
	src/client/camera.cpp
move glclear et all into client::render, makes more sense there.
but we need to glclear for the first init too
some z/camera fixes to get us on the right track

all hardcoded z back to 0.0 until i figure out znear/far
change tile z to 100 for testing
set passthrough matrix