Added closedIcon and openedIcon options
Merge pull request #127 from parktheredcar/feat/iconOptions

Added closedIcon and openedIcon options
Added screenshot image
Added link to docs and screenshot
Configured tree.jquery plugin to accept properties:{} config object to configure the name of the 'label' and 'load_on_demand' properties.
So you, can write:
$("#tree").tree({
    properties:{
        label: 'name',
        load_on_demand: 'hasChildren'
    }
});
Added example for using new 'properties' property.
Merge branch 'configurable' into gh-pages