Merge branch 'hotfix/1.18.8' into stable
Update JRuby to 1.7.3

JRuby 1.7.3 came out today:
https://twitter.com/jruby/statuses/304644544199274496
Merge pull request #1561 from LeifWarner/update_jruby_to_1.7.3

Update JRuby to 1.7.3
1.18.9
Merge pull request #1561 from LeifWarner/update_jruby_to_1.7.3

Update JRuby to 1.7.3
Merge branch 'hotfix/1.18.9'