Update gh-pages to 9d0499c4

commit 9d0499c4306f44e5c2153e4ddd6e2b06928e7e18
Author: Richard Klancer <rpk@pobox.com>
Date:   Tue Apr 29 10:43:48 2014 -0400

    Land Mgmt: adjust plant protective effect
    
    [#69731272]

commit a9aed97a2e05b08bd206052c887841d4470f4c4a
Author: Richard Klancer <rpk@pobox.com>
Date:   Fri Apr 25 14:34:51 2014 -0400

    Land Mgmt: prevent most edge effects
    
    [#69730958]
    
    Seems to work fairly well.

commit 47cf06eeb470d68b7ce8e3c87005e6811a75069d
Author: Richard Klancer <rpk@pobox.com>
Date:   Mon Apr 28 14:01:25 2014 -0400

    Land Mgmt: require simple-statistics pkg
    
    [#69730958]
    
    Not too huge, & probably better practice than hand-coding even a simple linear regression.