Added an update on load feature for plugins. Thanks Raphfrk!

Any files placed in the configurable update folder are automatically copied into the plugins directory the next time a reload happens. This allows safe updating of the plugin .jar files. The name of the update folder is configurable through bukkit.yml.

By: EvilSeph <evilseph@unaligned.org>

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -87,6 +87,7 @@ public final class CraftServer implements Server {
         configuration.getString("database.password", "walrus");
         configuration.getString("database.driver", "org.sqlite.JDBC");
         configuration.getString("database.isolation", "SERIALIZABLE");
+        configuration.getString("settings.update-folder", "update");
     }
 
     public void loadPlugins() {
@@ -239,6 +240,10 @@ public final class CraftServer implements Server {
 
     // End Temporary calls
 
+    public String getUpdateFolder() {
+        return this.configuration.getString("settings.update-folder", "update");
+    }
+
     public PluginManager getPluginManager() {
         return pluginManager;
     }