fixes for thread start race condition
missed one queue() -> enqueue() rename coverage
tell ac to try to use C99 or equiv standard
bumped version to 3.01, compatible with varnish major version
Merge branch 'release/3.01' into develop

* release/3.01:
  bumped version to 3.01, compatible with varnish major version
  tell ac to try to use C99 or equiv standard
  missed one queue() -> enqueue() rename coverage
  fixes for thread start race condition