18 chain saw manuals added

18 more chain saw manuals and parts lists were added recently, for the following brands:

- Craftsman: 1 chain saw manual, 1 chain saw parts list
- Husqvarna: 1 chain saw manual, 3 chain saw parts lists
- Jonsered: 1 chain saw manual, 2 chain saw parts lists
- McCulloch: 1 chain saw parts list
- Poulan: 3 chain saw parts lists
- Poulan Pro: 1 chain saw parts list
- Stanley: 4 chain saw manuals