Fix for bug #20888 (https://gna.org/bugs/?20888), the autoscaling of Grace graphs.

This solution was mentioned in the post at
http://thread.gmane.org/gmane.science.nmr.relax.devel/3920/focus=3930.

Instead of using minimum and maximum values for the axes in the Grace graphs produced by the
lib.software.grace module, which was the old solution for having the graphs scaled to reasonable
values, instead the '@autoscale' command is appended to the end of all graphs.  This is performed by
the write_xy_data() function.
Fix for the Noe.test_noe_analysis system test.

This is needed due to the Grace graph autoscaling changes of r20037.
Bug fix for the running of the test suite in the relax GUI.

The fix of r19727 was extended to apply to the GUI as well.  Too many arguments were being sent into
TextTestRunner Python class on certain Python versions (3.1 and <= 2.6).
Big bug fix - the relax execution lock now truly supports nesting.

This fixes bug #20891 (https://gna.org/bugs/?20891) reported by Troels Linnet
(https://gna.org/users/tlinnet).  Scripts can now be executed from the GUI.

Note that this is a very dangerous fix.  Playing with the relax execution lock often proves fatal,
so this commit may have to be reverted.
Completed the fix for bug #20889 (https://gna.org/bugs/?20889).

The problem was that the spectrum.read_intensities user function was incorrectly updating the
cdp.spectrum_ids list when the spectrum_id argument is set to a list.  The list of IDs was being set
as a single element of cdp.spectrum_ids, causing problems with the GUI when updating the ComboBox
choices and then subsequent setting of the spectrum IDs.

This bug and fix is independent of the relax_disp branch, despite being uncovered there and being
caught by the Relax_disp.test_bug_20889_multi_col_peak_list GUI test in that branch.
Manually ported r20048 from the relax_disp branch where it was deleted to the trunk.

.....
  Partial fix for bug #20889 (https://gna.org/bugs/?20889).
  
  The peak intensity wizard now detects when the spectrum ID argument of the first page is set to a
  list.  The default value for all subsequent user functions is now set to the first element of that
  list.
.....
Added an EPS version of the 128x128 pixel spectrometer icon.

This is for use in the relax manual.
Fix for the spectrometer 128x128 EPS icon - the background was black.
Added a README file for the relax 128x128 icons describing how the EPS files should be created.
Updated the spectrometer 128x128 icon to be of the correct size and colour.
Added a README file to the graphic/analyses directory describing how to create the EPS files.
Merger of the dipole_pair and interatomic user function classes.

The functionality of these two classes overlaps significantly.  And the dipole_pair user functions
are not related to magnetic dipole-dipole interactions.  Therefore all the user functions from both
classes were shifted into the new interatom user function.

This change will affect almost all relax scripts but, as this will form part of the relax 3 release,
script breakage should be expected anyway.
Removed the pipe_control.dipole_pair module as its contents is now in pipe_control.interatomic.
Removed the dipole_pair module from the pipe_control package __all__ list.
Merged the interatom.create user function into interatom.define.

These user functions had overlapping functionality which would be confusing for a user.
Added polish to all of the interatom user function docstrings.
Improved the functionality of the interatom.read_dist user function.

The file data is now stripped using lib.io.strip to remove comments and blank lines.  And now if the
iteratomic data container cannot be found, it is created instead of raising a RelaxError.
Improvements to the RelaxZeroVectorWarning - the warning message was terribly out of date.
Bug fix for the GUI element for the interatom.define user function.

The special spin ID GUI elements can not be set to the get_spin_ids() function as then SetValue can
no longer work for IDs not in the list.  This fixes the Mf.test_mf_auto_analysis GUI test.
Polish for the rdc.read user function.

Comment lines and blank lines are now removed to suppress useless warning messages about these lines
containing no valid data.