ruby 1.8 throws IndexError instead of KeyError
Revert "Revert "Merge pull request #62 from dlupu/master""

This reverts commit 6af738f3984a644372266ac6d4b7557cbdf040e1.
Merge branch 'fix-18-keyerror' into review-62
Merge pull request #75 from intridea/review-62

Review pull #62: respond_to? 1.9