Include more "golden" contrib

Starting in 6.x-2.x, we included an aegir contrib module (Hosting Platform Pathauto) in our makefile, and thus the Aegir distribution. I think that particular module should just be integrated into Hosting, since it's really pretty simple. But there are some fairly major sub-systems out in contrib right now that should perhaps be included in the same way. I have in mind particularly:

• hosting_site_backup_manager
• hosting_remote_import
• hosting_tasks_extra
• and maybe hosting_advanced_cron

Most of these have Provision extensions too, so that'd have to be taken into account...

These are all pretty stable, and used in production at most of the lead development shops. In addition, the Aegir core maintainers are also maintainers of most of these extensions anyway. Further usage, and thus bug-fixing (and the usual Free Software virtuous cycle) should stabilize them even more.

So why not just merge those projects under Aegir itself? Well, it'd essentially cut off non-core maintainers from helping to maintain these sub-systems. In fact, I think we should really consider spinning off a number of other components in a similar fashion. I'd suggest the following:

• quotas
• dns
• cron_queue (essentially deprecated)
• signup form

The idea would be to re-include them by default, but spinning them off as separate projects would allow additional contributors to participate in maintaining them. I believe this would be a good way to on-board potential core maintainers.