Add check for latest version

Shows a message if the version of cheesecake is outdated

src/static_include.rs

@@ -16,11 +16,16 @@ struct Assets;
 pub fn static_file<'r>(file: PathBuf) -> Result<(ContentType, Cow<'static, [u8]>), Status> {
     let filename = file.display().to_string();
     let d = Assets::get(&filename).ok_or(Status::NotFound)?;
-    let ext = file
+    let mut ext = file
         .as_path()
         .extension()
         .and_then(OsStr::to_str)
         .ok_or(Status::InternalServerError)?;
+    // ContentType::from_extension normally returns None for map files, but they should be sent with
+    // the JSON mimetype
+    if ext == "map" {
+        ext = "json"
+    }
     let content_type = ContentType::from_extension(ext).ok_or(Status::InternalServerError)?;
     Ok((content_type, d.data))
 }

static/scripts/main.ts

@@ -1,6 +1,14 @@
+declare const version;
 declare const initial_chats;
 declare let chats;
 
+// Check if cheesecake is up to date
+$.getJSON("https://api.github.com/repos/cubetastic33/cheesecake/releases/latest", result => {
+    if (result["tag_name"] !== version) {
+        $("#outdated").show();
+    }
+});
+
 let $backup = $("#backup");
 
 function show_toast(message, duration = 2000) {