Tools update

Some changes to the tools in the e3 wrapper.

Most notably: clone-all uses clone-group in the same way that build-all uses build-group.

Also added an option for build-group-modules to "start at a certain point"; i.e. if building a group fails partway through, it's nice to start at that point onwards.

Lastly, I fixed the issue where a failing build would sometimes continue onwards. The issue is that set -e is unreliable and doesn't propagate upwards, so if you run into a build error while using build-all-modules.sh, it would not stop, but continue trying the next group.