Improve javadoc in 26 files.

Addresses:
BUKKIT-1643, BUKKIT-1868, BUKKIT-1846, BUKKIT-2632, BUKKIT-3196,
BUKKIT-3187, BUKKIT-3198, BUKKIT-3200, BUKKIT-3201 and BUKKIT-3417.

By: feildmaster <admin@feildmaster.com>

paper-api/src/main/java/org/bukkit/scheduler/BukkitTask.java

@@ -9,28 +9,28 @@ import org.bukkit.plugin.Plugin;
 public interface BukkitTask {
 
     /**
-     * Returns the taskId for the task
+     * Returns the taskId for the task.
      *
      * @return Task id number
      */
     public int getTaskId();
 
     /**
-     * Returns the Plugin that owns this task
+     * Returns the Plugin that owns this task.
      *
      * @return The Plugin that owns the task
      */
     public Plugin getOwner();
 
     /**
-     * Returns true if the Task is a sync task
+     * Returns true if the Task is a sync task.
      *
      * @return true if the task is run by main thread
      */
     public boolean isSync();
 
     /**
-     * Will attempt to cancel this task
+     * Will attempt to cancel this task.
      */
     public void cancel();
 }