Improve logging when generating multilingual book

lib/output/generateBook.js

@@ -77,6 +77,7 @@ function processOutput(generator, startOutput) {
             return;
         }
 
+        var logger = book.getLogger();
         var books = book.getBooks();
         var outputRoot = output.getRoot();
         var plugins = output.getPlugins();
@@ -94,6 +95,8 @@ function processOutput(generator, startOutput) {
                 plugins:    plugins
             });
 
+            logger.info.ln('');
+            logger.info.ln('generating language "' + langBook.getLanguage() + '"');
             return processOutput(generator, langOutput);
         });
     })

lib/output/preparePages.js

@@ -1,4 +1,5 @@
 var Parse = require('../parse');
+var Promise = require('../utils/promise');
 
 /**
     List and prepare all pages
@@ -10,6 +11,10 @@ function preparePages(output) {
     var book = output.getBook();
     var logger = book.getLogger();
 
+    if (book.isMultilingual()) {
+        return Promise(output);
+    }
+
     return Parse.parsePagesList(book)
     .then(function(pages) {
         logger.info.ln('found', pages.size, 'pages');