Make all autonyms unique and add a test for this

In a list of languages to select autonyms must be unique so that
every user would know what to select.

* Batak Toba language in the Batak writing variant (bbc-batk) has
  an autonum in the right script now. This is taken from the Indonesian
  Wikipedia article "Surat Batak".
* Similarly to the practice with pa -> pa-guru:
  * iu for Inuktitut in the Canadian script redirects to ike-cans.
  * ks for Kashmiri in the Arabic writing redirects to ks-arab.
  * tg for Tajik in the Cyrillic script redirects to tg-cyrl.
* zgh has an updated autonym, taken from Ethologue.
* zh-classical redirects to lzh, similarly to zh-yue -> yue.

test/jquery.uls.test.js

@@ -20,7 +20,7 @@
 
 	module( 'jquery.uls' );
 
-	var orphanScripts, badRedirects, doubleRedirects, languagesWithoutAutonym;
+	var orphanScripts, badRedirects, doubleRedirects, doubleAutonyms, languagesWithoutAutonym;
 
 	/*
 	 * Runs over all script codes mentioned in langdb and checks whether
@@ -59,6 +59,31 @@
 		return result;
 	};
 
+	/*
+	 * Runs over all languages and checks that all autonyms are unique.
+	 */
+	doubleAutonyms = function () {
+		var language, autonym,
+			autonyms = [],
+			duplicateAutonyms = [];
+
+		for ( language in $.uls.data.languages ) {
+			if ( $.uls.data.isRedirect( language ) ) {
+				continue;
+			}
+
+			autonym = $.uls.data.getAutonym( language );
+
+			if ( $.inArray( autonym, autonyms ) > -1 ) {
+				duplicateAutonyms.push( language );
+			}
+
+			autonyms.push( autonym );
+		}
+
+		return duplicateAutonyms;
+	};
+
 	/*
 	 * Runs over all languages and checks that all redirects point to a language.
 	 * There's no reason to have double redirects.
@@ -99,7 +124,7 @@
 		assert.ok( $.fn.uls, '$.fn.uls is defined' );
 	} );
 
-	test( '-- $.uls.data testing', 30, function ( assert ) {
+	test( '-- $.uls.data testing', 31, function ( assert ) {
 		var autonyms,
 			languagesToGroup, groupedLanguages;
 
@@ -126,6 +151,7 @@
 		assert.deepEqual( badRedirects(), [], 'All redirects have valid targets.' );
 		assert.deepEqual( doubleRedirects(), [], 'There are no double redirects.' );
 		assert.deepEqual( languagesWithoutAutonym(), [], 'All languages have autonyms.' );
+		assert.deepEqual( doubleAutonyms(), [], 'All languages have distinct autonyms.' );
 
 		assert.strictEqual(
 			$.uls.data.getGroupOfScript( 'Beng' ),