Some cosmetic changes

[kwankyu]

implemented issue #48

also fixed #18 (comment)

See https://github.com/kwankyu/trac_to_gh/wiki/27996

and fixed problems in #18 (comment)

See https://github.com/kwankyu/trac_to_gh/wiki/34393

[kwankyu]

I am not sure if bold texts are too many or too few. Feel free to change them further.

[mkoeppe]

Thank you!

[mkoeppe]

I've made a small change to it in 16ffce4

[mkoeppe]

On ticket #14648 I am getting

  File "/Users/mkoeppe/s/sage/trac-to-github/./migrate.py", line 657, in commits_list
    _, commit_id, commit_message, _ = c.split('|')
ValueError: too many values to unpack (expected 4)

[mkoeppe]

Working around it in 4c22fe4

[kwankyu]

Working around it in 4c22fe4

I have a fix. Would you revert this?

[mkoeppe]

You can revert my workaround in your PR

[mkoeppe]

Also https://github.com/sagemath/trac_to_gh/blob/main/Issues-27xxx/27533.md#comment:1 is affected by a parsing error