Clean up checks for non-portable pthread extensions, and add a check for pthread_mutex_islocked_np() (not present on any platform I know of, but I am testing a FreeBSD patch)
Clean up checks for non-portable pthread extensions, and add a check for
pthread_mutex_islocked_np() (not present on any platform I know of, but I
am testing a FreeBSD patch)


git-svn-id: 7d4b18ab7d176792635d6a7a77dd8cbbea8e8daa@2419 d4fa192b-c00b-0410-8231-f00ffab90ce4

ssm/pkg-varnish,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,CartoDB/Varnish-Cache,ssm/pkg-varnish,wikimedia/operations-debs-varnish,ssm/pkg-varnish,CartoDB/Varnish-Cache,wikimedia/operations-debs-varnish,CartoDB/Varnish-Cache,ssm/pkg-varnish,ssm/pkg-varnish