relax SVN archive

Fix for the relax status object install_path variable.

This was using the 'relax_errors.py' file to determine the installation path, but this file no
longer exists.

Updated the test_suite.unit_tests package __all__ list.

The "from __future__ import absolute_import" statement is used in lib.io and lib.warnings.

This is to avoid module name clashes with the standard Python modules.

Deletion of a debugging printout statement.

Renamed the relax_warnings module to lib.warnings.

This is part of the relax library redesign.

Rearrangements for the unit tests of the old relax_io module (now lib.io).

Renamed the relax_io module to lib.io.

This is part of the relax library redesign.

Renamed the relax_string module to lib.text.string.

This is part of the relax library redesign.

Renamed the relax_errors module to lib.errors.

This is part of the relax library redesign.

Deletion of the frame_order_testing branch - this code has now been manually merged into trunk.