FEATURE: new 'simultaneous_uploads' site setting

config/locales/client.en.yml

@@ -2093,7 +2093,7 @@ en:
         upload: "Sorry, there was an error uploading that file. Please try again."
         file_too_large: "Sorry, that file is too big (maximum size is {{max_size_kb}}kb). Why not upload your large file to a cloud sharing service, then share the link?"
         too_many_uploads: "Sorry, you can only upload one file at a time."
-        too_many_dragged_and_dropped_files: "Sorry, you can only upload 10 files at a time."
+        too_many_dragged_and_dropped_files: "Sorry, you can only upload {{max}} files at a time."
         upload_not_authorized: "Sorry, the file you are trying to upload is not authorized (authorized extensions: {{authorized_extensions}})."
         image_upload_not_allowed_for_new_user: "Sorry, new users can not upload images."
         attachment_upload_not_allowed_for_new_user: "Sorry, new users can not upload attachments."

config/locales/server.en.yml

@@ -1470,6 +1470,8 @@ en:
 
     min_ratio_to_crop: "Ratio used to crop tall images. Enter the result of width / height."
 
+    simultaneous_uploads: "Maximum number of files that can be dragged & dropped in the composer"
+
     enable_flash_video_onebox: "Enable embedding of swf and flv (Adobe Flash) links in oneboxes. WARNING: may introduce security risks."
 
     default_invitee_trust_level: "Default trust level (0-4) for invited users."

config/site_settings.yml

@@ -1031,6 +1031,11 @@ files:
     default: 0.45 # 90% of 18:9
     min: 0
     max: 1
+  simultaneous_uploads:
+    client: true
+    default: 5
+    min: 0
+    max: 20
 
 trust:
   default_trust_level: