pkg-haskell-tools with sbuild unshare backend

[PICCA Frederic-Emmanuel <frederic-emmanuel.picca@synchrotron-soleil.fr>]

Hello, 

I dig a bit into the pkg-haskell-tools and try to adapt the make-all part to the new unshare sbuild backend[1].

I want to use dht for all kinds of packages and not only the haskell packages and also to make it easier to setup thanks to the new sbuild. 

The idee is to prepare a directory <repository> which will contain all the <packages> I wanted to rebuild and then just run 

  dht make-all --unshare --input <directory> --output lab

to build all of them.

- I removed the hard coding of the "p" directory (still de default)
- I decoupleg the packages name and the directory where the debian directory is hosted.
  * before p/<packages> where <package> is the source name
  * now p/<packages> where <package> is free. it means that a simple apt source <packages> can generate an usable <package> directory.

So I would like your opinion on my patches and If you could test it on your side in order to check that I did not broke our tool :).
This is a work in progress but I do not want to take a wrong direction.

For now the only contrain is to add the sbuild configuration. in ~/.config/sbuild/config.pl

$unshare_bind_mounts = [ { directory => "/dev/shm", mountpoint => "/sharedshm" } ];

thanks for your attention

Frederic

[1] https://salsa.debian.org/picca/pkg-haskell-tools