Create drush function for the ofed_requirements module

As discusse with Bart, there is no longer need of a specific drush implementation for that.

It will be handled using shell scripts and already existing drush functionalities.

Do we still need the module then ?

Is it used by the builders or can it be removed ?

Some parts of the module are definitely in need for an overhaul but basically, it provides something similar to Features, in that it shows differences between coded values and database's one. It works for roles, permissions, content types, ...

And on top of that, it provides some text fields allowing the builder to explain/justify the differences.

If the module has not been used yet, maybe it should be removed.

The "review" page is accessible at /admin/openfed/requirements