R1:709d7ed5d7e4

Use the proc-error-aware signaling check for daemons from the CLI

Summary:
The web console already correctly checks for processes which are running but
can't be signaled. Share this check in the CLI.

Test Plan:
Looked at the web console. Poked at the CLI.

Reviewed By: fratrik
Reviewers: fratrik
CC: aran, fratrik
Differential Revision: 544