Second attempt to supervise Process actions without Closures. #DPP-81

Following @hyperthunk instructions:

* Renamed type ChildRun to ChildStart
* Renamed constructor RunChan to StartChan
* Moved filterInitFailures fn bellow tryStartChild fn
* Replaced innerTryStartChild private fn with a case statement
* Renamed wrapExtProcess private fn to wrapChanProcess
* Renamed processChildRun fn to processToChildStart
* Renamed closureChildRun fn to closureToChildStart
* Removed link on restarterPid when creating child process oin processToChildStart