11 more chain saw manuals added

11 more chain saw manuals and parts lists were added recently:

- DeWalt: 1 chain saw manual
- Echo: 2 chain saw manuals, 3 chain saw parts lists
- McCulloch: 3 chain saw parts lists
- Sovereign: 1 chain saw manual
- Stihl: 1 chain saw manual

Sovereign chain saw manuals

Operating instructions:
- Sovereign PCS38Z 37cc Petrol Chain Saw
- Sovereign SCS 37/1 Petrol Chain Saw (Mar 2010)
- Sovereign SCS 38/45 Petrol Chain Saw (with parts)