Tidyup: Don't bind-mount /run/lirc into the test-pack container

We now use lirc over TCP rather than Unix domain socket.
tests: Add additional logging to make debugging easier
http-service: Fix typo

This commit actually has no effect, but the intent is clearer as test_grep
is now always a list.
http-service: Add endpoint for getting job status

`/api/v1/run_tests` no longer blocks until the test is finished.  It
returns a job id immediately which can then be used to track the progress
of the job using `/api/v1/jobs/<job_id>` which will tell you when a job
is complete, and in the future more information about the job in progress.
http-service: Add support for tracing

If the `STBT_TRACING_SOCKET` environment variable is set `stb-tester` will
log information about its current state to the unix domain socket referred
to by that variable.  With this commit we create such a socket and expose
any state written to it on the REST API.  This includes the currently
executing line number.
Merge branch 'tracing'

Conflicts:
	http-service/test-pack.bundle