relax SVN archive

Added import statements for the 'warn()' function and RelaxErrors and RelaxWarnings.

Bug fix.

A small rearrangment of the RelaxWarning module was required.

Renamed the RelaxError and RelaxWarning modules.

The 'errors' module is now called 'relax_errors' and the 'warnings' module is now 'relax_warnings'.

Fixed the diffusion tensor data structure unit test module by importing the RelaxError class.

Rearranged the setting of global variables in the RelaxError and RelaxWarning modules.

Removed all of the temporary Debug flags from the 'data.diff_tensor' module.

These are now unnecessary as this code is now functional in the 1.3 line.

Bug fix:

Modified the relax base directory path setting in the diffusion tensor data structure unit test
module so that the join() function would not throw an error if the path was not long enough.

A small change fixing the Debug flag to make the system tests work again.

Added the RelaxError import statement for the 'data.diff_tensor' module.

Removed the nesting of the RelaxWarnings and added the global variables Debug, Pedantic, and relax.