86967b2e35 Add option to use docker for gitian-build.sh (Andrew Chow)
Pull request description:
Updates gitian-build.sh script for the docker virtualization method recently added to gitian-builder.
Second commit depends on https://github.com/devrandom/gitian-builder/pull/185
Tree-SHA512: 0fa50b6c1be35a7a39f4a82816369637d3d0082922ac9876b80ae8156c795dec0ff34ad384b5348777042df8ddb6a72bbaeddd7002ef80557b10e2acf46632aa
--setup Set up the Gitian building environment. Uses LXC. If you want to use KVM, use the --kvm option. Only works on Debian-based systems (Ubuntu, Debian)
--detach-sign Create the assert file for detached signing. Will not commit anything.