re-classify bundled lua scripts

* search by author:
  - "Ardour Team" for "ready to use" plugins
  - "Ardour Lua Task Force" = example plugins

* search by Category
  - use "Example" for DSP plugins (except instruments)

scripts/rewind.lua

@@ -1,6 +1,8 @@
 ardour {
 	["type"]    = "EditorAction",
 	name        = "Rewind",
+	author      = "Ardour Lua Task Force",
+	description = [[An Example Ardour Editor Action Script.]]
 }
 
 function factory (params)