* test/TestCmd.py (TestCmd.cleanup): Print the names of preserved
directories. Reset self._dirlist even if directories are preserved.
* test/BoostBuild.py (Tester.cleanup): New method.
[SVN r14489]
* test/TestCmd.py: Cause the names of preserved directories to be
printed.
* test/test_system.html: Document "PRESERVE*" environmental variables
and "pass_test"/"fail_test" methods.
[SVN r14389]