Update to rra-c-util 5.10 and C TAP Harness 3.4
Update to rra-c-util 5.10: * Add missing va_end to xasprintf implementation. * Fix Perl test suite framework for new Automake relative paths. * Improve portability to Kerberos included in Solaris 10. * Use appropriate warning flags with Clang (currently not warning clean). Update to C TAP Harness 3.4: * Fix segfault in runtests with an empty test list. * Display verbose test results with -v or C_TAP_VERBOSE. * Test infrastructure builds cleanly with Clang warnings. * Support comments and blank lines in test lists.