test of newsyslog, as they were mainly made to test 'newsyslog -t',
but they do test the basic functionality.
The test 'framework' was based on dds@'s code in
src/tools/regression/bin/mv/.
Note that currently these tests are not fully correct for the
non-timestamp based rotation case, as it seems like newsyslog actually
by default keeps a file too much around.
MFC after: 3 weeks
