Add development policies section to devref

We now have a whole bunch of unwritten development policies about what is
allowed and what isn't, it is time to write some of them down.

A subsequent patch will add the first policy.

Change-Id: I91c2eb2b937f38b3b3c5380ac93fa0ce0f5e4156
Add out of tree support dev policy

Record what our policy is around supporting out of tree code.

Change-Id: I718ef7f0b6c29a85be89292d051f07b4cdd32676
websocketproxy: remove leftover debug output

Someone reported the following very long entry in their
/var/log/messages:

  Jun  6 15:00:16 gprfc041 nova-novncproxy: }}>>{<{<}>{<{<}> [...]

It turns out that this is from some debug code left in this module.
Just drop it.

Change-Id: I392f599e81790376dab11f9323430ee9abcff444
Merge "Add development policies section to devref"
Merge "Add out of tree support dev policy"
Merge "websocketproxy: remove leftover debug output"