tests: prepare to move ./defs to t/ax/test-init.sh We don't do this in a sweeping passage, because that would cause endless headaches in the synchronization between the maint, master and ng/master branches. Instead, we setup our framework to allow test scripts to work by sourcing either './defs' or 'test-init.sh', so that we'll be able to make the transition gradual and painless. * t/ax/test-init.sh: New, copied from the previous ./defs file. * defs: Simply work by sourcing the new file. * Makefile.am (dist_noinst_DATA): List the new file. * t/README: Adjust to mandate the sourcing of 'test-init.sh' rather than of './defs'. * t/c-demo.sh: Source 'test-init.sh' instead of ./defs. This is done to verify our new setup actually works. * t/ac-output-old.tap: Likewise. Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>