Credits screen: update for 2.0

Props boonebgorges

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8238 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
humans.txt: update for Mercime

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8239 cdf35c40-ae34-48e0-9cc9-0c9da1808c22