* Added test_corrupted_root() to test_scan.py. Resolves issue #97.
* Added test_prune_long_missing() and test_prune_short_missing(). Resolves issue #91.
* Added test_prune_long_updated() and test_prune_short_updated(). Resolves issue #90.
* Added test_skip_recent_long_with_recent() and test_skip_recent_short_with_recent(). Resolves issue #93.
* Added test_skip_recent_long_with_old() and test_skip_recent_short_with_old(). Resolves issue #92.
* Added test_expr_option(). Resolves issue #95.