peer: get fresh list of peers if no new peers for 30 minutes.

We always ask a new peer for their peers, but ask every peer every
30 minutes as well.  We only start this once we've reached a peer,
and push it back every time we reach a new one.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ccan/cdump: import.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ecode_names, pkt_names: generate using ccan/cdump.

The sed command worked, but this is a nice test for cdump.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Makefile.in: make 'test' a real alias for 'check'

Travis uses make test.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>