relax SVN archive

Renamed the generic_fns package to pipe_control.

This huge change is part of the relax package layout redesign.

Removed the ancient relax data model redesign document.

This was started in 2006 and has long been completed.

Updated the package layout document.

Switched to a different sectioning style in the test suite.

The relax test suite now uses the functions from lib.text.sectioning for more consistent titles.

Merged the generic_fns.sys_info module into the info module.

Renamed the generic_fns.relax_re module to lib.regex.

Added a sanity unit test for the lib package to make sure it is the relax lib package.

Updated the lib package __all__ list.

Spun out some functions of generic_fns.model_selection into the new lib.model_selection module.