HPCC-8961 Add ulimits for enabling huge page support

Signed-off-by: Mark Kelly <mark.kelly@lexisnexis.com>

Two init script changes required for using huge pages which should be ok for all distributions

In addition, memory needs to be reserved for huge pages, which can be done on most
distributions by editing sysctl.conf:

# add a small dedicated region (128*2M = 256MB)
vm.nr_hugepages = 128
# add room for huge page region to grow to max (4096 *2M = 8GB for example)
vm.nr_overcommit_hugepages = 4096

NOTE: huge page mem regions are not swappable and cannot be overcommitted