Allow NTLM authentication when building using SecureTransport (Darwin) for SSL.
This uses CommonCrypto, a cryptography library that ships with all versions of
iOS and Mac OS X. It's like OpenSSL's libcrypto, except that it's missing a few
less-common cyphers and doesn't have a big number data structure.
- Renamed st_ function prefix to darwinssl_
- Renamed Curl_st_ function prefix to Curl_darwinssl_
- Moved the duplicated ssl_connect_done out of the #ifdef in lib/urldata.h
- Fixed a teensy little bug that made non-blocking connection attempts block
- Made it so that it builds cleanly against the iOS 5.1 SDK
