Add mappings to what-cursor-position for ga and g8

Hi! So I did another small merge request: https://gitorious.org/evil/evil/merge_requests/2 It adds mappings to what-cursor-position for ga and g8. These commands are different in Vim, and perhaps g8 should run what-cursor-position with a numeric argument. What do you think? I don’t really know what to think of merge requests. It doesn’t feel like they’re a lot easier to do than using format-patch. And you don’t easily get the same discussion around them that you would on the mailing list.