Added the API for spawning primed TNTs

git-svn-id: http://mc-server.googlecode.com/svn/trunk@1605 0a769ca7-a7f5-676a-18bf-c427514a06d6
Added a crude limiter for explosions sent to client.

Now the client can survive even 3000k TNT blocks exploding without jerking much.

git-svn-id: http://mc-server.googlecode.com/svn/trunk@1606 0a769ca7-a7f5-676a-18bf-c427514a06d6