BibEdit: improvements for master

1: D400 First line should end with '.', not ':'
1: D205 Blank line missing between one-line summary and description
1: D208 Docstring is over-indented
1: I101 copyright is missing
2:1: W191 indentation contains tabs
3:1: W191 indentation contains tabs
5:1: E302 expected 2 blank lines, found 0
5: D103 Docstring missing
7:1: W191 indentation contains tabs
8:1: W191 indentation contains tabs
9:1: W191 indentation contains tabs