Enable long-running commands that can be terminated or interrupted.

[SlaunchaMan]

This PR adds the ability for the Mac host to launch commands that run asynchronously. For instance you can use simctl io to record video during your UI tests. To do this, there are four new commands added as siblings of exec:

• launch begins a process
• status reports the process of a status, including its standard input/output
• interrupt sends a SIGINT signal to the process and reports its status back
• terminate sends a SIGTERM signal to the process and reports its status back

Processes are identified by UUIDs to avoid any potential conflicts with process IDs.

[tcamin]

There's a small conflict to resolve, other than that looks good. 👍🏻

[SlaunchaMan]

Awesome, thanks for merging so quickly!

[tcamin]

Thanks for the great addition!

…

On Sat, 18 Jan 2020 at 23:49, Jeff Kelley ***@***.***> wrote: Awesome, thanks for merging so quickly! — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#3?email_source=notifications&email_token=AAGVUEPFLHUEISTZRLLAUWLQ6OBRNA5CNFSM4KH3B5RKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJKDVSY#issuecomment-575945419>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAGVUEJVRGIWJ4EP56D3DE3Q6OBRNANCNFSM4KH3B5RA> .