[WORKER] Support LB timeout options

Parse the new loadBalancers.options section of the UPDATE JSON
message to set various timeouts and retry values. These options
can be set per-protocol. Timeout values are assumed to be in
milliseconds, with the default being 30000 ms for the timeouts
and 3 for the retry value.

Example JSON message:

{
  "hpcs_action": "UPDATE",
  "loadBalancers": [
     "protocol": "http",
     "options": {
         "client_timeout": "30000",
         "server_timeout": "30000",
         "connect_timeout": "30000",
         "connect_retries": "3"
     },
     ...
  ]
}

Change-Id: I45a6b9c85e8fc282ac80fa3f0eae0193e08e9756