Some updates

Move setting up the available parallelism and call stacks into their own
functions

Replace some uses of QT_ENV_S with sizeof(actual_var)

Remove the comments on the include files. Some of them aren't accurate and we

change verbosity == 2 to verbosity >= 2

No longer set number of threads, or WORKER_UNIT if the user set QT_NUM_WORKERS
or QT_NUM_WORKERS_PER_SHEPHERD (assume "expert" user.)