use `String#shellsplit` for the arg to `Kernel#exec`
use `String#shellsplit` for the arg to `Kernel#exec`

if a command is executed as `Kernel.exec("ruby my-app.rb with args")
it will be ran in a `sh -c "…"`, and we will get the PID of that one,
which results in orphaned processes. `String#shellsplit` results in:
`Kernel.exec("ruby", "my-app.rb", "with", "args")` which does the
right thing.

fgbreel/bluepill,bluepill-rb/bluepill,sferik/bluepill,sferik/bluepill,dealpath/bluepill,iroller/bluepill,iroller/bluepill,d-unseductable/bluepill,bluepill-rb/bluepill,d-unseductable/bluepill,fgbreel/bluepill,dealpath/bluepill