Added k_AB to parameters.

Progress sr #3071: https://gna.org/support/index.php?3071 - Implementation of Tollinger/Kay dispersion model (2001)
Following the guide at: http://wiki.nmr-relax.com/Tutorial_for_adding_relaxation_dispersion_models_to_relax

Troels E. Linnet provided this patch. Commit by: tlinnet _aaattt_ gmail_dot_com

Signed-off-by: Edward d'Auvergne <edward@nmr-relax.com>
More fixes for the relax_disp.exp_type user function changes.
Merged revisions 20912 via svnmerge from 
svn+ssh://bugman@svn.gna.org/svn/relax/trunk

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  r20912 | bugman | 2013-09-06 17:27:22 +0200 (Fri, 06 Sep 2013) | 3 lines
  
  Removed a debugging printout.
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Removed some debugging printouts fatal for Python3.
Merged revisions 20915-20919 via svnmerge from 
svn+ssh://bugman@svn.gna.org/svn/relax/trunk

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  r20915 | bugman | 2013-09-06 18:10:17 +0200 (Fri, 06 Sep 2013) | 5 lines
  
  The compat.SYSTEM is now set to 'Windows' when 'Microsoft' is detected.
  
  This is for easier identification of MS Windows systems, as either string could be used.
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  r20916 | bugman | 2013-09-06 18:39:56 +0200 (Fri, 06 Sep 2013) | 6 lines
  
  Created the new gui.text module for holding all of the unicode text for the GUI.
  
  This module contains unicode strings for the various analysis types, which are then all defined in
  one location.  This is for consistency.
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  r20917 | bugman | 2013-09-06 18:44:56 +0200 (Fri, 06 Sep 2013) | 3 lines
  
  Converted the model-free user function definitions to use the new gui.text module strings.
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  r20918 | bugman | 2013-09-06 18:57:26 +0200 (Fri, 06 Sep 2013) | 3 lines
  
  Shifted the gui.text module to lib.text.gui to avoid a fatal circular import in the GUI.
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  r20919 | bugman | 2013-09-06 19:01:13 +0200 (Fri, 06 Sep 2013) | 3 lines
  
  MS Windows fixes for the GUI for missing unicode font glyphs.
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The relaxation dispersion GUI elements now use the lib.text.gui module for unicode strings.
Merged revisions 20922 via svnmerge from 
svn+ssh://bugman@svn.gna.org/svn/relax/trunk

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  r20922 | bugman | 2013-09-06 19:38:03 +0200 (Fri, 06 Sep 2013) | 3 lines
  
  Added some Mac OS X GUI string fixes for missing unicode characters to lib.text.gui.
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Some unicode text fixes in the dispersion GUI analysis for older MS Windows versions.