Log Message:
Separate the package files from the test directory.  This means that the
tests may be run in any directory writable by the user.  It also means that
there will be no cleanup of the test directory if the package is removed.
Specifically, the following changes were made.

- Install most package files into PREFIX/libdata/boost-test-suite.
- Teach boost-test-suite to copy files from there into the test directory.
- Add a command line option (-b) to define the test directory.  By default,
  the directory is determined by the value of BOOST_TEST_BASEDIR at the 
  time the package is built.  This may be configured in mk.conf, but is
  /var/boost otherwise.
- Reverse the sense of the -c command line option to mean that the test
  directory SHOULD be cleaned.  Previously, cleaning was done by default.