13 more auto manuals added

13 more auto owner's manuals and other documentation were added recently, for the following brands:

Chevrolet:
   - 1 service bulletin

Honda:
   - 1 owner's manual
   - 1 owner's manual supplement
   - 7 online reference owner's manuals
   - 1 warranties booklet

Pontiac:
   - 2 owner's manuals