Add timer based plugins

[Bremaweb]

This adds plugins that run on a timer. After the timeout is reached their execute function runs.

[mwgg]

Hi

Thanks for the contribution!

However, while test-running your version alongside mine, I've noticed that it tends to stop executing commands either after the first one, or any at all. It doesn't seem to get past "if ( isset($this->actions->plugins[$command]) ) {".

I'm too sleepy to figure out what's happening at the moment, perhaps you have a clue.