Fix meta, add server.list_files

Gotta be careful what file access we give, but this much should be safe

src/main/java/net/aufdemrand/denizen/scripts/commands/BukkitCommandRegistry.java

@@ -1868,7 +1868,7 @@ public void registerCoreMembers() {
         // This will fully load a midi song file stored in the '../plugins/Denizen/midi/' folder. The file
         // must be a valid midi file with the extension '.mid'. It will continuously play the song as
         // noteblock songs at the given location or group of players until the song ends. If no location or
-        // entitiy is specified, by default this will play for the attached player.
+        // entity is specified, by default this will play for the attached player.
         //
         // Also, an example Midi song file has been included: "Denizen" by Black Coyote. He made it just for us!
         // Check out more of his amazing work at: http://www.youtube.com/user/BlaCoyProductions
@@ -1877,15 +1877,15 @@ public void registerCoreMembers() {
         // None
 
         // @Usage
-        // Use to play a midi song file on the current player
+        // Use to play a midi song file on the current player/
         // - midi file:Denizen
 
         // @Usage
-        // Use to play a midi song file at a given location
+        // Use to play a midi song file at a given location/
         // - midi file:Denizen <player.location>
 
         // @Usage
-        // Use to play a midi song file at a given location to the specified player, and wait for it to finish.
+        // Use to play a midi song file at a given location to the specified player(s), and wait for it to finish.
         // - ~midi file:Denizen <server.list_online_players>
 
         // -->

src/main/java/net/aufdemrand/denizen/tags/core/ServerTags.java

@@ -437,6 +437,25 @@ public void serverTag(ReplaceableTagEvent event) {
             return;
         }
 
+        // <--[tag]
+        // @attribute <server.list_files[<path>]>
+        // @returns dList
+        // @description
+        // Returns a list of all files in the specified directory. The starting path is /plugins/Denizen.
+        // -->
+        if (attribute.startsWith("list_files") && attribute.hasContext(1)) {
+            File[] files = DenizenAPI.getCurrentInstance().getDataFolder().listFiles();
+            if (files == null) {
+                return;
+            }
+            dList list = new dList();
+            for (File file: files) {
+                list.add(file.getName());
+            }
+            event.setReplaced(list.getAttribute(attribute.fulfill(1)));
+            return;
+        }
+
         // <--[tag]
         // @attribute <server.has_permissions>
         // @returns Element(Boolean)