Make our Windows users happy, add PFX private key support to the crypto, tls and https modules.
@bnoordhuis, Manual memory management is always painful. We can use smart pointers(unique_ptr), but the problem is they are available only in c++11 or boost.
Alas, that's not an option. It's not allowed to use STL / TR1 / Boost or > C++98 features.
Crypto: support of .pfx or .p12
crypto: add PKCS12/PFX support