Implemented ability to have server settings. Currently cache directory is there but it is not configurable (or used in this commit)

API/Interfaces/ITaskScheduler.cs

@@ -5,5 +5,9 @@
         public void ScanLibrary(int libraryId, bool forceUpdate = false);
 
         public void CleanupVolumes(int[] volumeIds);
+        /// <summary>
+        /// Clears the cache directory entirely.
+        /// </summary>
+        public void ClearCache();
     }
 }