revid-cli: can't send to vidrecord anymore in -NetSender mode

[Saxon Milton]

Now that -NetSender mode has revid do nothing until it gets vars from netreceiver, we can no longer do http sending to vidrecord in this mode. We did http sending to vidrecord in this mode because our httpSender depends on an ns for http sending. I propose that if we're not in -NetSender mode, that we check for http output, and if we have http output, then we create an ns just for this purpose. This way we will also solve the problem of needless ns.Run() calls that were occuring previously when doing vidrecord sending in -NetSender mode.

Alternatively, we could remove the dependency that httpSender has on netsender.

[Alan Noble]

A couple of strategies with pros and cons:

1) VidRecord returns vars to revid-cli (so it is compatible with NetReceiver), or

2) revid-cli implements a new -Record mode.

I lean towards (1) since VidRecord already implements the vars method. It would be trivial to add the following vars:

Output=Mpegts HttpAddress=localhost:8080

[Saxon Milton]

Resolved in PR #160. Vidrecord on iotsvc was also altered such that is can send vars to revid including desired outputs.