Gearman monitoring

[sadlil]

Gearadmin will now expose metrics. Custom metrices will look loke this.

# HELP gearman_server_client_count Count Connected Clients
# TYPE gearman_server_client_count gauge
gearman_server_client_count 0
# HELP gearman_server_job_count Count jobs
# TYPE gearman_server_job_count gauge
gearman_server_job_count 0
# HELP gearman_server_worker_count Count Connected Workers
# TYPE gearman_server_worker_count gauge
gearman_server_worker_count 1
# HELP gearman_server_worker_running_job_count Running Job By workers
# TYPE gearman_server_worker_running_job_count gauge
gearman_server_worker_running_job_count{worker="tigerworks"} 0