provide more fine-tuned optimization variables in control_vars.conf for node.cfg to be used in zeekdeploy.sh

[mmguero]

@ObsidianKnife suggested better ways to fine-tune node.cfg for performance as it's created by zeekdeploy.sh on the hedgehog. See cisagov#158

I'm going to for now add the following to control_vars.conf:

export ZEEK_PIN_CPUS_LOGGER=
export ZEEK_PIN_CPUS_MANAGER=
export ZEEK_PIN_CPUS_PROXY=
# zeekdeploy.sh will also check and use (if present):
#   ZEEK_PIN_CPUS_WORKER_1 .. ZEEK_PIN_CPUS_WORKER_n
# where n is the number of capture interfaces

in addition, this existed in there previously:

export ZEEK_LB_PROCS=1
export ZEEK_LB_METHOD=custom

These variables will be used in creating node.cfg to add optional (only created if defined) pin_cpus sections for logger, manager, and proxy, and for each worker (1 .. n where n is the number of capture interfaces). Additionally, for the workers' lb_procs values, I will use the following order of preference, if they exist:

1. ZEEK_LB_PROCS_WORKER_1 .. ZEEK_LB_PROCS_WORKER_n
2. the number of pinned CPUs in ZEEK_PIN_CPUS_WORKER_1 .. ZEEK_PIN_CPUS_WORKER_n
3. the value in ZEEK_LB_PROCS (defaults to 1)

[mmguero]

Released in Malcolm v2.6.1