Fix bug where examples always used AFSSLPinningModeNone
Remove all _AFNETWORKING_PIN_SSL_CERTIFICATES_ conditions

Fixes #1098
Update documentation re: _AFNETWORKING_PIN_SSL_CERTIFICATES_
Remove reference to _AFNETWORKING_PIN_SSL_CERTIFICATES_
Add adn certificate to Mac example
Merge pull request #1100 from dstnbrkr/remove-conditional-compilation

Remove conditional compilation (_AFNETWORKING_PIN_SSL_CERTIFICATES_)