relax SVN archive

Renamed the lib.algebra package to the more appropriate lib.linear_algebra.

Converted the target_functions.frame_order from a package into a module.

The full package is no longer required as all modules have been shifted into lib.frame_order.

Shifted most of the modules of target_functions.frame_order to lib.frame_order.

Shifted the target_functions.frame_order.pec module to lib.geometry.pec.

Renamed the pipe_control.frame_order module to lib.frame_order.format.

Fixes for the generic_fns to pipe_control renaming.

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.