Add jruby-1.7.16.1

1.7.16.1 is a security fix release for CVE-2014-8080. All users are strongly recommended to upgrade.

http://jruby.org/2014/10/28/jruby-1-7-16-1.html

Am I missing something after the `#` sign in the URI to the download? What should be there, if anything? A SHA1?