Update to ejabberd 13.12 (squashed)

Update to ejabberd 13.12

- includes PostgreSQL support option
- includes MySQL support option
- can be built with Homebrew OpenSSL 1.0.1f and later (for TLS v1.1 and TLS v1.2 support)
- made Homebrew OpenSSL support unconditional
- replaced single quotes with double quotes
ejabberd: add 13.12 bottle.