Using check_PROGRAMS would postpone compiling the binaries needed by
system tests until `make check` would be called. Since it's preferable
to invoke pytest directly to run the system test suite, compile these
binaries without installing them during `make all` instead by using
noinst_PROGRAMS.
This removes the need to use TESTS= make -e check hack invoked from
pytest to work around this issue.
Tag the libraries with check_ to prevent them being installed
by "make install". Additionally make check requires .so to be
create which requires .lai files to be constructed which, in
turn, requires -rpath <dir> as part of "linking" the .la file.
the test-async plugin uses ns_query_hookasync() at the
NS_QUERY_DONE_SEND hook point to call an asynchronous function.
the only effect is to change the query response code to "NOTIMP",
so we can confirm that the hook ran and resumed correctly.
