Set up isolation for build-time

[xsawyerx]

We should be using chroot to build our modules. This allows us to divorce (and not depend) on system dependencies available on the host during build-time, and instead make sure we only have what we want.

We were able to avoid it so far, but we should approach it now.

This is related to #25.

[xsawyerx]

There is a successful usage using mock which needs to be documented. We could also provide a helper script.

We are now also packaging Pakket with Seacan and once that tool is merged, it will be documented and this ticket will be closed.