enable journal logging (#117)

* refactor silence msg handling and add tests

Signed-off-by: Chris Collins <collins.christopher@gmail.com>

* Improve handling of incident wait msg

Improves the waitForIncidentThenDo function, removing the unnecessary
sleep that may have been causing slow responsiveness in the TUI, and
consolidating specific "wait" functions into the generic
waitForSelectedIncidentThenDo function.

Signed-off-by: Chris Collins <collins.christopher@gmail.com>

* Enable journal/system logging

Enable logging to the system log location (/var/log, or Mac equiv.) or
the systemd journal if using systemd.

Signed-off-by: Chris Collins <collins.christopher@gmail.com>

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Signed-off-by: Chris Collins <collins.christopher@gmail.com>

Author: clcollins