Don't mark Rack responses as committed if using X-Sendfile (TORQUE-1240)

For sendfile support to work properly, we have to ensure any responses
using it don't mark the response as committed. But, for all other
responses, we do want to make the response as committed to prevent
recreating the issue fixed in TORQUE-1215.
Don't require a specific Rake version in torquebox-rake-support (TORQUE-1236)
Bump to JRuby 1.7.16.1
Permit the timeout period for a fetch call to be set via an optional :timeout parameter
Merge pull request #193 from jeremy-cc/master

Permit the timeout period for a fetch call to be set via an optional :ti...