Issue 146: Fix comma in encoded address header

[AndreasLF]

Fixes #146

Bug Fix

This change resolves the parsing error for address headers (like From:) that contain an encoded comma. The fix is to parse the raw header with email.utils.getaddresses before decoding with decode_header_part. This ensures the parser treats the encoded word as a single unit and doesn't split it.

Test Correction (for #136)

While implementing this fix, I discovered an issue with test_issue_136. The test was expecting the following output: [("", "notificaccion-clientes@bbva.mx"), ("", "notificaccion-clientes@bbva.mx"),]

I would argue that this is incorrect. The raw From header in that test file is: From: =?UTF-8?B?bm90aWZpY2FjY2lvbi1jbGllbnRlc0BiYnZhLm14?= <notificaccion-clientes@bbva.mx>

This header represents only one address, where the display name is just the encoded version of the email address. The parser correctly decodes the name, sees it's identical to the email, and returns an empty string for the name.

I have updated the test to expect the correct, single-address output: [("", "notificaccion-clientes@bbva.mx"),]

Let me know what you think.

[coveralls]

coverage: 99.232% (+0.003%) from 99.229%
when pulling ae02771 on AndreasLF:issue146
into 025f937 on SpamScope:develop.