relax SVN archive

Removal of all unused imports in the lib.dispersion package.

Added a script for testing the independence of the relax library.

Removed the dependency on the relax dep_check module from the relax library.

This is to further decouple the library from relax.

Divide by zero avoidance fix for the rotor frame order model module lib.frame_order.rotor.

Improved support for printing stack tracebacks with RelaxWarnings.

The '--traceback' command line option will now show a full traceback. A replacement
warnings.showwarning() function has been written to write out the traceback before the
warnings.formatwarning() replacement function is called.

Decreased the amount of newlines around the printout from the '--error-state' command line option.

The lib.errors module is now really independent of relax - the compat module is no longer used.

Instead, the Python 2 and 3 versions of the pickle module are imported using try statements.

Reordered the debugging command line options and removed the '-r' shortcut.

Created the '--error-state' command line option for saving a pickled state when a RelaxError is raised.

This gives greater control of a powerful feature added to relax by Chris MacRaild. The pickled
state can then be attached to bug reports or can be used to quickly load the state prior to failure
when in the scripting UI mode.

Clean up of the debugging command line options.

The debug flag now will cause stack tracebacks to be printed on all RelaxWarnings.