proposal: DROP DATABASE variant that kills active sessions

DROP DATABASE mydb CONCURRENTLY;

That would perform forced shutdown

1) reject any new backends to mydb
2) terminate old backends
3) drop db

40 upvotes here http://dba.stackexchange.com/a/11895/3710 inspired me
to propose this improvement.

If you think it's a good idea please include it as a low-priority TODO item.

thanks