Constructs an object that reflects the structure of an App Model
@method constructAppModel
@param id            unique key for app
@param name          unique key for app definition
@param label         unique user-defined display name for app
@param created       timestamp when app was created
@param lastUpdated   timestamp when app was last updated
@param status        status of app
@param features      enabled app features
@param signOnMode    authentication mode of app
@param accessibility access settings for app
@param visibility    visibility settings for app
@param credentials   credentials for the specified signOnMode
@param settings      settings for app
@param links         discoverable resources related to the app
@param embedded      embedded resources related to the app
@returns {}          the appModel object
function constructAppModel(id, name, label, created, lastUpdated, status, 
                            features, signOnMode, accessibility, visibility, 
                            credentials, settings, links, embedded) {
    var model = {};
    if(id) model.id = id;
    if(name) model.name = name;
    if(label) model.label = label;
    if(created) model.created = created;
    if(lastUpdated) model.lastUpdated = lastUpdated;
    if(status) model.status = status;
    if(features) model.features = features;
    if(signOnMode) model.signOnMode = signOnMode;
    if(accessibility) model.accessibility = accessibility;
    if(visibility) model.visibility = visibility;
    if(credentials) model.credentials = credentials;
    if(settings) model.settings = settings;
    if(links) model.links = links;
    if(embedded) model.embedded = embedded;

    return model;
}