Merge pull request #705 from hintjens/master

Fixed doc for IDENTITY socket option
Rename engine's methods to improve code readability
Merge pull request #706 from hurtonm/master

Rename engine's methods to improve code readability
Fixed out-of-source build
Merge pull request #707 from xantares/master

Fixed out-of-source build
Temporary workaround for broken libsodium install