lib/tests/test_log_message: convert misc testcases to use MSG_TESTCASE

Signed-off-by: Balazs Scheidler <balazs.scheidler@balabit.com>
nvtable: fix nvtable corruption in case an indirect value references itself

Whenever an indirect ref references itself, nvtable lookups become infinite
loops. Fix this by breaking the reference cycle in this case.

Signed-off-by: Balazs Scheidler <balazs.scheidler@balabit.com>
Merge pull request #328 from balabit/f/fix-segfault-for-self-referencing-values

F/fix segfault for self referencing values