Have you considered using Bountysource salt?
I can see there is a page on Bountysource salt, with the Dlang name on it[1], but it doesn't look like it's being used.

Nimlang[2] and Crystal[3] is using it with great success.

I think a lot of people would donate some money if you set some goals, made the page nice and posted an announcement about it ;)

Well, just a thought.

Regards, Nick

[1] - https://salt.bountysource.com/teams/d
[2] - https://salt.bountysource.com/teams/nim
[3] - https://salt.bountysource.com/teams/crystal-lang