Addresses #74 by adding ability to assign names to services

[xxxserxxx]

• Have you test the code?
• Have you check that the existing tests are passing?
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This change allows user to provide a -name <name> argument that will be used instead of the PID in supervisors for services added from the command line by non-root users. For example:

$ immortal -name top top -bn 5
$ immortalctl
    PID           Up   Down   Name      CMD
 ... <snip> ...
1676432   1h37m16.1s          1757      skippy-xd --start-daemon
2021609        13.8s          top       top -bd 5

After this, the usual immortalctl commands of stop, start, and halt using the name work as usual. This makes non-root usage much more convenient, e.g.:

$ immortalctl stop top

This addresses #74 in that it makes running immortalctl commands easier for users, as they do not have to first determine the supervisor PID. This will make scripting easier, as well.

As a design note, I first implemented this through the -ctl argument; however, it would have affected the behavior of the root use; immortal -ctl foo foocommand would have tried to use ~root/.immortal/ instead of /var/run/immortal as was the behavior prior to my change. Since this was a breaking change (whether or not it was much used), I went with adding a new argument.

-ctl and -name are not compatible; -ctl always overrides -name. One enhancement would be throwing an error if both are provided; that is not included in this patch.

I do not know why github is listing both changes in the diff, since the other patch has been accepted and merged. I find github's behavior baffling sometimes.