Passing provider to lookupAdapter in session#close, and passing options to adapter

This fixes session#close so that custom adapters will no longer cause a "not implemented" exception.
You should be able to use the `adapter` instance already looked up during setup.

```
var oldClose = apdater.close;
adapter.close = function(options){
  optionsCloseCalledWith = options;
  oldClose.call(this, options);
};