Ajax related fixes for command components

There are some minor problems with command links and buttons having an ajax behavior.

1) Both of them have to check in decode() if the request is a partial or behavioral submit to queue the action event for thos requests.
2) If a command link has a behavior with ClientBehaviorHint.SUBMITTING then the "normal" submit code should not be rendered.
3) For command link "normal" submit code was not escaped correctly before chaining.