gluon-neighbour-info: query direct neighbours

This is a simple client for gluon-announced.
gluon-neighbour-info: cleanup, use recv instead of recvfrom
gluon-neighbour-info: newlines between responses
gluon-neighbour-info: global timeout
Merge pull request #69 from freifunk-gluon/gluon-neighbour-info

gluon-neighbour-info: query direct neighbours