Cast string "array.id" to integer, makeClusterFunctionTorque with SSH

`asInt`expects a numeric input value. `array.id` as output from `Sys.getenv` is a string.

In a multi-node cluster site only one node may be able to accept Torque
commands. If this node is accessible via SSH, BatchJobs can run on any
other node tunnelling the Torque command to that node.