client/server added libfiu header files in --enable-libfiu-support mode
[test suite] minor fko_wrapper comment update
[test suite] in --enable-fuzzing-interfaces mode create fko-wrapper/send_spa_payloads file if it does exist
[test suite] added first test to run fwknop client underneath fiu-run for libc fault injection
use fiu.h instead of fiu-local.h
Revert "add gcc '-pg' flag in --enable-profile-coverage mode"

This reverts commit bbe5626566d617317f2d25f5650f2299c95f2c9f because -pg
is needed for gprof, not gcov, and valgrind is incompatible with -pg.