t/valgrind.suppress: Suppress another error in check.
t/: Include testwrapper.sh in the distribution tarball.
t/valgrind.suppress: Updated existing suppression for newer check version.

(Keeping the old around for people using the old version of check, e.g.
Travis.)
t/testwrapper: Let valgrind generate suppressions for all failures.

These are printed to stdout.
t/coverage.sh: Output the content of t/test-suite.log in case of a failure.
plugin: Report an error if a collector's interval cannot be determined.

Else, we'll get weird behavior when, for example, using LoadPlugin instead of
LoadBackend in sysdbd.
sysdb: Use non-callback readline mode when non-interactive.

libedit's implementation of the callback-mode does not play well in
non-interactive mode (e.g. it does not correctly detect EOF) but works fine
when using readline().

Also, there's no need for the somewhat more complex callback mode in
non-interactive operation anyway.
sysdb: Fixed a memory leak on EOF from the server.
t/integration/simple_query.sh: Pass in queries through stdin as well.

This covers some more code.
t/integration/simple_config.sh: Run the tools using -h and -V.
t/integration/simple_config.sh: Test reconfiguration.
t/integration/simple_config.sh: Test some more invalid settings.
store, frontend: Added support for matching NULL attributes.

This matches any hosts which are missing the specified attribute.
store_lookup_test: Added some tests for attribute.FOO IS NULL.