code review for 7067811: Update demo/sample code to state it should not be used for production

[Nils Loodin]

I've contacted Aurelio, and he has updated the bug with the additional 
demands. Also I've updated the webrev

(accessible here: http://cr.openjdk.java.net/~nloodin/7067811/webrev.02/ )

Added comment to each demo file (as stated in the bug), put a top level 
readme in the demo and sample dir containing a similar text.
So basically a comment block in a bunch of demo source files, and some 
updated makefiles..

I'll send the review out here first, and then to other lists as I get 
comments.

/Nisse