fix documentation for Record Types

Previously the documentation for `Record` included an example usage of
`Record.defrecord` that was missing a comma after the `name` argument.
This has been updated.
Merge pull request #2928 from jw2013/prefix

remove unnecessary function prefix
Merge pull request #2927 from mattfreer/fix/record_docs

fix documentation for Record Types
Improve the documentation of Enum.Sample/1,2