tests: split test libs into "generic" and "automake-specific" This is the first step in the quest to merge the generically useful parts of our test suite framework in a more generic project, like Gnulib. Time will tell if we'll succeed, and whether the success will be worth the extra hassle. * t/ax/test-init.sh: Split out ... * t/ax/am-test-lib.sh, t/ax/test-lib.sh: ... into these two tests. * defs, Makefile.am: Adjust. Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>