runner: Add support for aborting on network failure

If the network goes down while testing, CI tends to interpret that as
the device being down, cutting its power after a while. This causes an
incomplete to an innocent test, increasing noise in the results.

A new flag to --abort-on-monitored-error, "ping", uses liboping to
ping a host configured in .igtrc with one ping after each test
execution and aborts the run if there is no reply in a hardcoded
amount of time.

v2:
 - Use a higher timeout
 - Allow hostname configuration from environment
v3:
 - Use runner_c_args for holding c args for runner
 - Handle runner's meson options in runner/meson.build
 - Instead of one ping with 20 second timeout, ping with 1 second timeout
   for a duration of 20 seconds
v4:
 - Rebase
 - Use now-exported igt_load_igtrc instead of copypaste code
 - Use define for timeout, clearer var name for single attempt timeout

Signed-off-by: Petri Latvala <petri.latvala@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Martin Peres <martin.peres@linux.intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>