[Strategic] logo

[Steve Coast]

following the IRC i followed through and did the small work required for 
a patch to update it. I also updated the twitter @openstreetmap logo and 
people seem pretty positive. the usual edge cases, but bleh, you can't 
do anything without some pushback and anyone is free to help improve it.

I've sent a pull request to TomH too. So with a bit of luck the site 
will be updated.