Merge remote-tracking branch 'upstream/master'

Cargo.toml

README.md

openssl-sys/Cargo.toml

openssl-sys/src/build.rs

openssl-sys/src/lib.rs

src/bn/mod.rs

src/crypto/hash.rs

src/crypto/hmac.rs

src/crypto/pkey.rs

src/crypto/symm.rs

src/ssl/mod.rs

src/ssl/tests.rs

src/x509/mod.rs