Allows userscript files to work both as Greasemonkey scripts, and as BabelExt extensions

UserscriptCompatability.js

// Basically, dynamically selects between BabelExt and Greasemonkey methods,
//  depending on what is avalaible at runtime
//
// Simply put this at the top of your userscript, and use BE_set/getValue
//  exactly as you would BabelExt.storage.set/get
//
// However, there is also another argument passed to getValue, def, as in the
//  default value if none can be retrieved (as in Greasemonkey's GM_getValue)

function BE_setValue(key, val, callback) {
    if (typeof(BabelExt) != 'undefined') {
        BabelExt.storage.set(key, val, callback);
    } else {
        GM_setValue(key, val);
        callback.call();
    }
}
function BE_getValue(key, def, callback) {
    if (typeof(BabelExt) != 'undefined') {
        BabelExt.storage.get(key, callback);
    } else {
        callback.call(this, GM_getValue(key, def));
    }
}