Control: tags -1 + patch
Control: block -1 by 58658 58659

Hi,

This patch adds Gocryptfs to master. It's a file-based, encrypted
overlay file system inspired by EncFS—but better.

Since there are some exotic prerequisites, I placed the code in its own file.

Please note that Gocryptfs requires updates to go-golang-org-x-net [1]
and go-github-com-sabhiram-go-gitignore. [2] Those were filed
separately. Thanks!

Kind regards,
Felix Lechner

[1] https://debbugs.gnu.org/58658
[2] https://debbugs.gnu.org/58659