Revert "base: configure avahi to avoid SO_REUSEPORT"

This reverts commit b9746dcbc13d8d6c7e2227edf0abc75183476e66, restoring
avahi-daemon to the default configuration which requires SO_REUSEPORT.

Our kernel now has a backport of support for SO_REUSEPORT, as of git hash
5196e01 on 2014-09-16.  This kernel is available in the OLPC dropbox:

http://dev.laptop.org/~kernels/public_rpms/f20-xo4/

SO_REUSEPORT is also required by telepathy-salut for preparing the
multicast transport when an activity is shared.  The symptom is missing
shared activities in network neighbourhood.

See gibber-multicast-transport.c which calls setsockopt with
SO_REUSEPORT if it is defined.
sugar: suppress bundle inflate messages

During activity bundle install, every file in the bundle is listed in
output of olpc-os-builder, and this is not very useful.  A list of files
is already generated by the builder.
base: hack default route when using ad-hoc

On Fedora 20, when an ad-hoc network is connected, Sugar buddy icons and shared
activities are not shown in neighbourhood.  Activity logs contained "No
active connection available."  Salut logs contained "no connections, and
timed out."

It was discovered that configuring a default route avoided the problem,
though the mechanism by which this works is not known.

Add a Network Manager dispatcher script which creates a default route to
169.254.1.1 on eth0 up with matching connection ID and IP address.