BibEdit: improvements for master

1: D400 First line should end with '.', not ':'
1: D205 Blank line missing between one-line summary and description
25: D401 First line should be imperative: 'Return', not 'Returns'
25: D202 No blank lines allowed *after* function docstring, found 1
25: D400 First line should end with '.', not ':'
25: D205 Blank line missing between one-line summary and description