infrastructure and using that infrastructure in programs.
* MKHESIOD, MKKERBEROS, MKSKEY, and MKYP control building
of the infratsructure (libraries, support programs, etc.)
* USE_HESIOD, USE_KERBEROS, USE_SKEY, and USE_YP control
building of support for using the corresponding API
in various libraries/programs that can use it.
As discussed on tech-toolchain.