zsh: Colourise ls and grep on Ubuntu.

I don't like Ubuntu much, but because I have a VM that runs it
(_korra_, running Ubuntu 12.04 "Precise Pangolin"), I need to provide
a configuration for it.

One of the major pieces of pain that it offers is a lack of automatic
colourisation of stuff (which Fedora offers OOTB), so we use
`lsb_release` to get a release name and version.

I should probably point out that the most obvious way to parse
os-release is to source it, and, naturally, that's a PITA to do,
because it pollutes the environment, and zsh doesn't do scoping (as
far as I know).
Merge branch 'master' of elspeth:Documents/dot.files