Add module_pattern(s) module to DAM's toolbox

When trying to debug a feature of a specific module, site administrators are often asked to disable most or all other contrib modules to ensure that there is no conflict between some of them.

So it would be great if one could save the current state of enabled/disabled modules on admin/build/modules and revert to that state later on for testing purposes.

This should be provided in a separate sub-module of admin_menu, perhaps admin_devel.

Sure, this is quite outside the scope of DAM. But if we do this, we might be able to also move all the other developer features into this sub-module (and continue to work on the administrative menu API finally).