relax SVN archive

Fix for bug #21233 (https://gna.org/bugs/?21233) - the missing mpi4py multi-processor messages.

When multiple commands were being sent to one slave, the captured IO was being overwritten by each
executed command. Therefore the slave would only return the printouts from the last command.

Added the cluster graphic to the cluster section of the dispersion chapter and improved the text.

Added a 600x600 pixel graphic for the spin cluster for use in the user manual.

Removed most of the \clearpage commands in the dispersion chapter of the manual.

There was far too much whitespace.

Added a section to the dispersion chapter about spin clustering.

Fix for the sqrt() function in the dispersion parameter table.

Added a page ref back to the intro chapter in the scripting section of the dispersion chapter.

This is to help the user work out how to run a relax script.

Turned off the dw, dwH > 0 constraint for the 'MMQ 2-site' model.

Added dispersion curve plotting to the relax script for Korzhnev et al., 2005 MMQ data.

The 'MMQ 2-site' model target function can now handle multiple CPMG data types.