Due to a change in builder, nil values now generates closed tags, so instead of this: <pseudonyms nil=\"true\"></pseudonyms> It generates this: <pseudonyms nil=\"true\"/> Document this change in Rails so that people can track it down easily if necessary. Changes in Active Model, Active Record and Active Support tests. Cherry-pick of d65adc7, 77dd3be and 146eaf3. Fix build.
Reasons: * Markdown reads well as plain text, but can also be formatted. * It will make it easier for people to read on the web as Github formats the Markdown nicely. * It will encourage a level of consistency when people are writing CHANGELOG entries. The script used to perform the conversion is at https://gist.github.com/1339263