Ogr view model

Added an ogrItemViewModel that forwards files to our ogr2ogr service for conversion.
On drag and drop the file is uploaded to the server on a url it is loaded by the server.
Made this the default fall through for formats we don't have explicit handlers for.
Put 1MB size constraints on server and client side
Added airports.zip (shape file) to our init_test.json list

You could include that in the matcher function.  For example, change this:

    createCatalogItemFromUrl.register(matchesExtension('*'), OgrItemViewModel);

To this:

    createCatalogItemFromUrl.register(function(url) {
        // Match everything - except on browsers without FormData (IE9),
        // because OgrItemViewModel requires FormData.
        return typeof FormData !=== 'undefined';
    }, OgrItemViewModel);