If you remove the factory_girl line in the Gemfile, all the code should now be compatible with Ruby 1.8.7.
Making the code 1.8.7 compatible involved:
Removing all uses of the new hash symbol syntax (changing { key: value } to { :key => "value" }.
Using FasterCSV for CSV parsing when the Ruby version is 1.8.7.
Some changes around UTF-8 encoding.
Removing the server-side processing for the DataTables. I couldn't quickly figure out what the bug was with server-side processing in 1.8.7, but I disliked this change anyways (there aren't that many evaluations, so it's smoother to do it client-side; this also kept on introducing a bunch of other bugs in other people's CLs; all in all, kind of a needless complication, I think), so I removed it.
If you remove the factory_girl line in the Gemfile, all the code should now be compatible with Ruby 1.8.7.
Making the code 1.8.7 compatible involved:
{ key: value }to{ :key => "value" }.