Merge branch 'refs/heads/t/fec'

A single patch which improves the memory management of the
fec encoder.

Cooking for half a year.

* refs/heads/t/fec:
  vss: Fix NULL pointer dereference in vss_del_fec_client().
  vss: Rework fec client setup.

diff --cc NEWS.md
index de0aa1b462d3158e2325c383cd4cec7e569b46b9,de0aa1b462d3158e2325c383cd4cec7e569b46b9..6bd58962a55c4cda0d50d10815f84f1d7108fba9
--- 1/NEWS.md
--- 2/NEWS.md
+++ b/NEWS.md
@@@ -29,6 -29,6 +29,7 @@@ NEW
  - A fix for an old bug that could cause the server to crash or report
    garbage in its status output.
  - New para_play option: --end-of-playlist
++- Streaming m4a files over udp has been improved.
  
  --------------------------------------
  0.6.2 (2018-06-30) "elastic diversity"