v0.9.2

• Add constructors and accessors to PKey.
• Support PEM and DER encoding and decoding everywhere.
• Add PKey::bits.
• Add SslRef::set_tmp_{ec,}dh_callback and SslContextBuilder::set_tmp_{ec,}dh_callback methods.
• Add basic access to the X509_STORE in SslContextBuilder.
• Add constructors for standard primes to BigNum.
• Add a method to SslConnector that does not perform hostname verification.
• Use the ffdhe2048 standardized DH parameters in mozilla_intermediate configuration of SslAcceptor.
• Add support to decode and encode encrypted private keys.
• Add basic elliptic curve functionality.
• Move ec_key module to ec.
• Implement Clone for SslConnector and SslAcceptor.
• Add certificate and private key accessors to SslContext and Ssl.