Eina test model: Get offsets and sizes properly.
Eina test model: Get offsets and sizes properly.

Make the tests work on multiple platforms and also let people who read the
code see how to do it properly.

git-svn-id: a6113611d365f0fc061992be0d1d0b451b434026@67584 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

jordemort/eina,jordemort/eina,jordemort/eina