Review request 6831461

[Alan Bateman]

6831461: (sample) Copy -r fails with IllegalArgumentexception: 
'maxDepth' is negative

Sherman - this is bug in the Copy sample code that one of the tech 
writers ran into. For the -r option the sample code is calling 
walkFileTree with a max depth of -1 instead of Integer.MAX_VALUE. Not 
sure how I missed this but a reminder that we probably need to include a 
sanity check that runs the samples. The fix is trivial (and some other 
minor corrections to a comment and error messages):
    http://cr.openjdk.java.net/~alanb/6831461/webrev.00/

Thanks,
Alan.