Convert gen_app_yaml.py to optparse
This allows for example the -f flag to be specified as the second
argument. Also add a '-i|--interactive' flag which asks for the
application name interactively.
/**
* @param {Page[]} pages
* @param {number} [id] Specifies the id, if applicable.
* @param {String} [title = This is untitled.] Specifies the title.
*/
function Document(pages, id, title){
}