Fix #37, Offset the UDP base port per-CPU

[jphickey]

Describe the contribution
Avoid port conflicts when having more than one CPU within the same mission load CI_LAB app. Instead of binding to the port directly, add the CPU number as an offset. Subtract 1 so that CPU1 remains at the same port (1234 by default) and cmdUtil is not affected.

NOTE: the "cpu number" can be overridden on the command line when using the pc-linux PSP, thereby also permitting the listen point to be tuned for each launch config, if necessary.

Testing performed
Build using default config, ensure no errors.
Run FSW and test sending commands with cmdUtil - confirm no impact when using defaults, still listens on port 1234 as before and can send commands.
Run FSW using --cpuid 2 switch, confirm that listening port has changed, observing syslog trace:
1980-012-14:03:20.25227 CI_LAB listening on UDP port: 1235
Confirmed that cmdUtil still works to send commands if the --port 1235 option is given.

Expected behavior changes

• No behavior changes in the default/example config when also running with all defaults.
• CI_LAB changes its listening port when either using a config with multiple CPUs or using the --cpuid option to override (in pc-linux at least).

System(s) tested on

• Ubuntu 18.04 LTS, 64 bit

Contributor Info - All information REQUIRED for consideration of pull request
Joseph Hickey, Vantage Systems, Inc.

[jphickey]

Possible topic for CCB discussion:
This change leaves the default port at "1234", which is the old value, for compatibility but this fairly random.
It would be a little more user-friendly to make this e.g. "10000" or something like that, so that the numbers are a little easier to work with for humans.

[skliper]

My only concern related to this change was if the community was using CPU number for something else this association could cause breakage. That said it gets reported at startup, it's a lab app, and this solves a port collision issue and doesn't cause me any issues so I'm good with it.

[astrogeco]

CCB 20200318 - Approved

[astrogeco]

CCB 20200318 - Approved