[package] update avahi to included D-Bus support, libavahi-client library and avahi...

[package] update avahi to included D-Bus support, libavahi-client library and avahi-utils tools (#8929)

This updates the avahi package as follows:

1. The libavahi-client library can be selected.

2. The following avahi utilities can be selected:
   avahi-browse, aka: avahi-browse-domains
   avahi-publish, aka: avahi-publish-address, avahi-publish-service
   avahi-resolve, aka: avahi-resolve-address, avahi-resolve-host-name
   avahi-set-host-name.

Notes:
(a) This patch applies to avahi 0.6.29 -- I sent in the previous version
for 0.6.28 just after 0.6.29 came out, duh. :(

(b) The libavahi-client library and the avahi utilities require avahi to
be compiled with D-Bus support, and D-Bus must be included in
the build. If they are not selected, avahi is compiled without D-Bus
support, as it is at present.

(c) The init.d start priority of avahi-daemon is changed from 50 to 61
so that it loads after D-Bus.

The patch in Ticket #8929 has two problems, IMHO:
1. It makes the D-Bus package a compulsory requirement for avahi, even
though it's only really needed if you select the libavahi-client library.
(This patch makes D-Bus compulsory only if you select the
libavahi-client library or the avahi utilities which depend on them.)

2. The avahi-daemon will fail to start because the D-Bus daemon is set
to start up _after_ avahi-daemon starts looking for it.
(This patch adjusts the init.d start priority of the avahi-daemon to
later than that of D-Bus.)

Signed-off-by: Mike Brady <mikebrady@eircom.net>
git-svn-id: svn://svn.openwrt.org/openwrt/packages@26338 3c298f89-4303-0410-b956-a3cf2f4a3e73