Merge tag 'sparks-3.2.4' into develop

3.2.4
rework the lxc* tasks
peanuts.
avoid upgrades at every base() call.
use -g if we sudo NPM, else ~/ get borked.
Don't try to guess about the POOL implement of celery, just let the project implement it in settings.
don't use Fabric's execute(), it multiplies tasks a lot. We already do it in our execute_or_not(), which is more flexible.
bump version in __init__.py
Merge branch 'release/3.2.5'