[krbdev.mit.edu #600] install/autoconf options not all honored in all locations

[Ken Raeburn via RT]

Confirmed current trunk code (pre-1.3) appears to obey all --foodir
configure options.  Using just prefix and exec-prefix also appears
consistent, although since some of our headers are generated with
platform-specific data, we should change includedir to default to
${exec_prefix}/include.

Program name transforms are implemented in a bunch of places, but not
tested for completeness.