Add Recognition-Timeout as an Input attribute

Update to Rayo protocol to add support for `Recognition-Timeout` MRCP header in support of [Punchblock Pull Request 228 ](https://github.com/adhearsion/punchblock/pull/228).
I only chose seconds rather than milliseconds since that's how MRCP describes the setting. If we feel strongly, it's OK by me to change this to milliseconds.