BIND installation should be done by setting DESTDIR during "make
install" not by setting prefix via ./configure.
Make sure that installation with DESTDIR=<PATH> works by checking that
named binary and it's respective man page were installed and that
well-known BIND9 directories - and only them - are present in DESTDIR.
Also rename install path variable from BIND_INSTALL_PATH to
INSTALL_PATH to avoid namespace clash in stress tests which use
BIND_INSTALL_PATH variable to configure path to BIND9 binaries.
823bf3e79b