Fallback text as mentioned in Data API section not working about jquery.i18n

[alphadijkstra]

This issue is still there. I can trace it back to line 245 of jquery.i18n.js (version 1.0.5)

[timberger]

The problem is if the default texts which are in the Data API tags are not provide also in a language file the script will replace the innerText/innerHTML of the tags with the Data API key lines 169-171 in jquery.i18n.js

if ( message === '' ) {
	message = key;
}

A quick and dirty solution could to add something like this:

if ( message === '' ) {
	return document.querySelector('[data-i18n="'+key+'"]').innerHTML;
}

The result would be that current message would not change if there is no translation in the selected language.
But in my scenario the default message shall be given with the HTML on page load. (Why should i have also a languge file for the default language. It would require to keep them in sync and i have not found a tool that updates the language file when the messages in the HTML change.)
My idea is to add a function which reads all the messages from the Data API tags in the HTML file and add them to the messageStore on page load.

	function grab_defaults_from_data_api() {
		var deflocale = getDefaultLocale();
		var defaultmessages = document.querySelectorAll( '[data-i18n]' );
		if ( defaultmessages.length > 0 ) {
			var defaultmessagesobj = {
				"@metadata": {
					"authors": [
						"mr robot"
					],
					"last-updated": "1970-01-01",
					"locale": deflocale,
					"message-documentation": "qqq"
				}
			}
			for (var i=0; i < defaultmessages.length; i++) {
				defaultmessagesobj[ String(defaultmessages[i].getAttribute('data-i18n')) ] = defaultmessages[i].innerHTML;
			}
			$.i18n.messageStore.set(deflocale, defaultmessagesobj);
		}
	}

This function can be placed e.g. below getDefaultLocale() in jquery.i18n.js and call in the load function of I18N.

		load: function ( source, locale ) {
			var fallbackLocales, locIndex, fallbackLocale, sourceMap = {};
			
			grab_defaults_from_data_api();
			
			if ( !source && !locale ) {