Add support for .dat Mailparts by Thunderbird

[ghost]

New versions of Thunderbird with Enigmal and pEp send out Emails which, for the webview, arrive as a ".dat" file and an ".asc" file. One contains cleartext (empty and 0K if cleartext was nothing at all), the other contains the message. I never noticed this in my mail client up to now. This leads to Mail received from these versions of Thunderbird to be displayed (in runbox7 as well as the old version) as a simple empty Email with 2 files attached.

Because we can't - and not everybody necessarily wants to - decrypt the encrypted Message part, at least the .dat part should be displayed. Now I have not much recent Thunderbird experience. The dat file could come from Thunderbird itself, it could also be part of the Enigmal with prettyEasyprivacy part. I'm in touch with prettyEasyprivacy and could reach out to them to clarify the situation if you can't find a solution.

[gtandersen]

@ng-0 Thanks for your suggestion! We would certainly be interested in a discussion with p≡p about a possible integration.

@petersalomonsen @hernan604 @davidbowdley @kservik This could be an alternative or addition to PGP support which we are currently planning. Ref: https://www.pep.security

[ghost]

@gtandersen I'll get back to you with more details. Since I don't think people will appreciate pasting in details here, I will email support@ unless you recommend another address at runbox?

I'm a GNUnet developer, and we have some intersection of people involved in gnunet-related projects, some where p≡p are contributing and involved.

[gtandersen]

Thanks @ng-0, much appreciated.