Give props to Martin Pool

Martin Pool was the original author of the code referenced in the clone
example. Make note that he's given his permission and also give him the
proper credit.
Merge pull request #1364 from martinwoodward/thank-martin

Give props to Martin Pool
Increment reference counter in git_repository_set_config

This fixes #1365
Merge pull request #1368 from scunz/inc_ref

Increment reference counter in git_repository_set_config