[avahi] proposal for avahi service configuration directory change

[Jason Whitlark]

Hi all,

With regards to /etc/avahi/services, I propose we move to the apache 2 style of service configuration, i.e.
services-available and services-enabled directories with symlinks from the latter to the former.  This would have three
benefits that I can see:

1) Easily enable/disable services, particularly through 3rd party applications.
2) Management of services would be obvious.
3) Allows us to ship sample configurations, allowing people to be productive with avahi much faster and increasing adoption.

The code change should be trivial, the only real issue is upgrading prior installations to the new method.  I'm a
systems administrator, and had /etc/avahi been configured this way, I'd have immediately understood how it all worked,
and looked in services-available for examples.  Instead I had to spend time reading through docs and searching for
examples.  Not the end of the world, but for something that can be improved, especially for a technology called zeroconf.

What do you think?

Cheers,

~Jason