tap/awk: don't redirect awk stderr to log files * lib/tap-driver.sh: Handle the file descriptors redirections more smartly, to avoid sending error messages from awk (about e.g. syntax or I/O errors) to the log files instead that to the console. * tests/tap-driver-stderr.test: New test, verifying the improved driver behaviour. Notice that this test still fails when using the perl implementation of the TAP driver. * tests/Makefile.am (tap_other_tests): Update.