[Modules] Abort on error

[Xavier D. <xav...@gm...>]

Dear All,

A new configuration option named "abort_on_error" is added to define
whether module commands should continue on error or abort on error when
evaluating a sequence of modulefiles.

Details and example are available at:

https://modules.readthedocs.io/en/latest/MIGRATING.html#abort-on-error

Regards,
Xavier