Documentation improvement on Deployment

[Costis]

While searching for info about Play! framework I noticed that some people think that a Play! app cannot be deployed on a servlet
container. Maybe it should be noted in the relevant documentation section that deployment is possible on a servlet container and on cloud infrastructures such as GAE and and Stax.

Information from the following pages could be useful to someone who is interested to know about possible deployment cases

http://www.playframework.org/modules/gae
http://wiki.stax.net/w/index.php/Play
http://groups.google.com/group/play-framework/browse_thread/thread/fae2470d90abd209#