Update build-infra ref
Merge pull request #27 from Metaswitch/ccstor44

Reviewer: Alex Hockey - Fix https://github.com/Metaswitch/clearwater-build-infra/issues/13
Take latest sas-client
Take latest cpp-common
Take mainstream version of gcovr
Merge pull request #28 from Metaswitch/gcovr_update

[Reviewer: Andy] Take mainstream version of gcovr
Merge remote-tracking branch 'origin/diameter_decode' into live-test-fixes
Preserve logs on upgrade
Merge pull request #29 from Metaswitch/preserve_logs

[No reviewer required] Preserve logs on upgrade
Don't generate dependencies for extra test objects
Merge pull request #30 from Metaswitch/test_obj_deps

[No reviewer required] Don't generate dependencies for extra test objects
Merge remote-tracking branch 'origin/master' into live-test-fixes
Don't dereference NULL pointers
Revert incorrect .depends rules
Scale out thread count