RFD: Rework/extending functionality of mdev

[Harald Becker]

Hi Laurent !

>   Note that events can still be lost, because the pipe can be broken
> while you're reading a message from the netlink, before you come
> back to the selector; so the message you just read cannot be sent.
> But that is a risk you have to take everytime you perform buffered IO,
> there's no way around it.

To make clear, about what case we talk, that is:

- spawn conf parser / device operation process
- exit with failure
- re-spawn conf parser / device operation process
- exit with failure
- re-spawn conf parser / device operation process
- exit with failure
- ...
- detect failure loop
- spawn failure script
- exit with failure or not zero status
- giving up, close read end of pipe
- let fifosvd die

@Laurent: What would you do in that case?

Endless respawn? -> shrek!

--
Harald