Squashed commit of the following:

commit 7f59ee27d28ce89660c453d96e9f939259f5239d
Author: jonty-dawson-eegeo <jonty.dawson@eegeo.com>
Date:   Fri Dec 5 14:45:00 2014 +0000

    MeshExample - add web loading of texture, and demonstrate setting material on renderable after construction.
    Buddy: Salva

commit bba2a7da6fe6d0276d10c5b40e3dc9ae79f199b2
Author: jonty-dawson-eegeo <jonty.dawson@eegeo.com>
Date:   Fri Dec 5 12:12:15 2014 +0000

    MeshExample periodically flattens environment. ExampleMeshRenderable configurable to scale and/or translate to match environment flattening.
    Buddy: Ian

commit a5fa5e55eca9c9a39737f1824cdf5871f16b58c4
Author: jonty-dawson-eegeo <jonty.dawson@eegeo.com>
Date:   Thu Dec 4 18:31:00 2014 +0000

    add MeshExample, demonstrating creating a Mesh programatically, creating renderable instances and material, and drawing. Buddies: Mark, Ian