Updage gh-pages to 991fd4a958

commit 991fd4a958512332290664978f9c7f73472c8777
Author: Richard Klancer <rpk@pobox.com>
Date:   Thu Apr 24 10:09:26 2014 -0400

    Land Mgmt: move topsoil count graph
    
    [#69728404]

commit 67d84b88c646382170e2e76f83b76a13c4e7031f
Merge: a233532 0f4a3c8
Author: Richard Klancer <rpk@pobox.com>
Date:   Thu Apr 24 09:50:37 2014 -0400

    Merge branch 'master' into topsoil-count-graph
    
    Conflicts:
        land-management/app/src/erosion-engine.coffee

commit 0f4a3c8385f981e292f1e5abfff49662baa521bc
Author: Richard Klancer <rpk@pobox.com>
Date:   Thu Apr 24 09:45:54 2014 -0400

    Land Mgmt: decrease slope-slider range
    
    [#69731212]
    
    This avoids the "ledge" effect

commit a87f0fa0e1fcb5a24551de462ec05dcc750d37cf
Author: Richard Klancer <rpk@pobox.com>
Date:   Wed Apr 23 22:36:31 2014 -0400

    Land Mgmt: refactor erosion protection
    
    [#69731272]
    [#69731318]

commit 539ae50e79ac0d5286527ea89169cec91fe30df5
Author: Richard Klancer <rpk@pobox.com>
Date:   Wed Apr 23 16:44:39 2014 -0400

    Land Mgmt: simplify erosion algorithm
    
    [#69730958]

commit 89c9ab46c9ae88a0f4ec92e63353247b7555c853
Author: Richard Klancer <rpk@pobox.com>
Date:   Wed Apr 23 15:17:01 2014 -0400

    Land Mgmt: minimize edge effects in localSlope
    
    [#69730958]

commit 0f4060c2fead0ac813f926599945f0f114ff55fd
Author: Richard Klancer <rpk@pobox.com>
Date:   Wed Apr 23 14:14:56 2014 -0400

    Land Mgmt: Nate's changes to Netlogo version

commit 137784f99ee9db51a3cf7ee8abb478b9bc7c0b7c
Author: Richard Klancer <rpk@pobox.com>
Date:   Tue Apr 22 16:51:19 2014 -0400

    Land Mgmt: make grass "lives forever"
    
    [#69730884]

commit edcab436d770d8daeb342df7b4a15ac76e14a1ae
Author: Richard Klancer <rpk@pobox.com>
Date:   Tue Apr 22 14:07:26 2014 -0400

    Land Mgmt: fix jittering of eroder particles.
    
    [#69726412]
    
    The local variable 'direction' was not being copied back to the patch's property 'direction'. There was no good r

commit 3555d8f105048dbf9b523a44bc36d72e0ef4a90d
Author: Richard Klancer <rpk@pobox.com>
Date:   Tue Apr 22 13:49:19 2014 -0400

    Land Mgmt: fix cant-plant-perennials-twice bug
    
    [#69727506]

commit 925dbe5ffb32b18b53aadf70d8d2c47bbe8e885f
Author: Richard Klancer <rpk@pobox.com>
Date:   Tue Apr 22 11:41:05 2014 -0400

    Air Pollution Aerial:fix click-to-create-factories
    
    [#69932484]
    
    The click-to-create-a-factory feature was not working in Firefox, because the event handler relied on the nonstan