local scheduler for heterogenous jobs
copied from cf-staging / aitchaitch (pronounced like the letter H) implements a light-weight
cluster-style scheduler for use on a single workstation. Unlike parallel,
xargs, and other similar utilities, which presume that all jobs use
the same amount of resources, aitch permits one to request a different
amount from an arbitrary number of unique kinds of resources. In effect
it implements a counting semaphore for each resource and provides a
means to adjust their values by non-negative integers.
