Improve Locale batch progress and result messages

First of all I like the changes. The screenshot illustrates the improved UI very well. Reviewing the patch I also like that concrete file names are now replaced by project names. We want to automate file downloads and imports for users, so the files are just a means of getting the translations and users will have no exposure to them. The download and import is all automated. So it is internal detail at this point and we don't need to put that burden on the user to understand. There are also different things intertwined in the batches, and the general progress is clearly visible while more user friendly messages help the user to understand what is going on currently. My only concern is the application of the project name display:

+++ b/core/modules/locale/locale.batch.incundefined
@@ -54,7 +54,7 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
-    $context['message'] = $t('Checked translation file: %name.', array('%name' => $source->name));
+    $context['message'] = $t('Checked translation for %project.', array('%project' => $source->project));

@@ -248,7 +249,7 @@ function locale_translation_batch_fetch_download($project, $langcode, &$context)
-        $context['message'] = $t('Imported translation file: %name.', array('%name' => $file->filename));
+        $context['message'] = $t('Downloaded translation for %project.', array('%project' => $source->project));

@@ -308,7 +309,7 @@ function locale_translation_batch_fetch_import($project, $langcode, $options, &$
-          'message' => $t('Importing translation file: %name', array('%name' => $file->filename)),
+          'message' => $t('Importing translation for @project.', array('@project' => $source->project)),

@@ -318,7 +319,7 @@ function locale_translation_batch_fetch_import($project, $langcode, $options, &$
-            $context['message'] = $t('Imported translation file: %name.', array('%name' => $file->filename));
+            $context['message'] = $t('Imported translation for %project.', array('%project' => $source->project));

@project or %project does not seem to be consistently applied.

Looks good otherwise!

I don't think using !message is bad, the output of t() is assumed to be "secure" as long as the input was (appropriate placeholders are used for replacement data).

Looks good to me.

Committed to 8.x.

Woot, thanks!