EEP proposal - Delayed restarts of supervisor children

[Viktor Söderqvist]

Hi Maria!

I support this EEP. :-)

It has been argued before that supervision trees are for fault-tolerance 
of bugs, not network/external errors. But why not enable the use of 
supervision subtrees for external faults too?

If we add delays, then how about exponential backoff? e.g. doubling the 
delay for each failed restart attempt. Is it worth considering too? It 
has been suggested before and it's common for network re-attempts.

Loic:
>> If 'undefined' and 0 are equivalent, let's just drop 'undefined' and
>> make 0 the default. No need to complicate things further.

Maria:
> [...]  _any_ integer value makes no sense for temporary children, not even 0.

Just forbid the existence of the key restart_delay when restart type is 
temporary.

Viktor