drop Twitter support

See http://www.die-welt.net/2012/09/why-i-hope-twitter-will-die-with-the-new-api/ for details.

@Twitter: YOU SUCK!

git-svn-id: https://plugins.svn.wordpress.org/statusnet-widget/trunk@706342 b8457f37-d9ea-0310-8a92-e5e31aec5664
also drop Ohloh support

See http://meta.ohloh.net/2012/02/journals-going-away/ for details.

git-svn-id: https://plugins.svn.wordpress.org/statusnet-widget/trunk@706343 b8457f37-d9ea-0310-8a92-e5e31aec5664
release 0.5: the dead of the backends release

git-svn-id: https://plugins.svn.wordpress.org/statusnet-widget/trunk@706344 b8457f37-d9ea-0310-8a92-e5e31aec5664