[ubuntu-za] Global Jam Cape Town Poster suggestion

[maia grotepass]

> also a dash of Aubergine would make it more revoutionary.

David, my first version was all aubergine with glowing white text, but
I read that aubergine is supposed to communicate Canonical-ness. The
grey background logos are actually low opacity aubergine :D

I'll post the first version for interest sake tonight, and maybe an
update with mascots.