relax SVN archive

More modifications to the sequence input GUI window to match the multiple file selection element.

The window now starts with a single element rather than nothing.

Removed a debugging printout statement accidentally committed at r22235.

Added a 'Delete' button to the sequence input GUI window.

This is to match the multiple file selection GUI window. The button allows the user to delete the
last item from the list. So if 'Add' has been clicked too many times, the user does not have to
start again from scratch by clicking on 'Delete all'.

Modified the GUI window for inputting sequence data to include item numbers.

An non-editable initial column with the number of each item has been added. This is to help the
user when, for example, the items of one sequence element should match another (for example in the
spectrum.read_intensities user function where multiple file names should match multiple spectrum
IDs).

Fixes for the unit tests of the spectrum.read_intensities user function.

A number of checks were not correctly set up, and the recent changes caused others to now fail.

Created the test_loop_exp_frq() dispersion unit test.

This checks the operation of the loop_exp_frq() function from the module
specific_analyses.relax_disp.disp_data. It uses the data attached to the bug report at
https://gna.org/bugs/?21665.

Renamed the test_loop_exp_time() dispersion unit test to test_loop_exp_frq_offset_point_time().

This is for the specific_analyses.relax_disp.disp_data.Test_disp_data.test_loop_exp_frq_offset_point_time()
unit test. The name better reflects the function being tested.

Small spacing fix.

Improved the behaviour of the multiple file selection GUI window.

The RelaxFileDialog GUI element is now initialised when the file selection button is clicked rather
than in the __init__() method. The result of this change is that the current working directory is
dynamically changed in the RelaxFileDialog, hence if the directory is changed in one file selection
element, it will look like it is changed in all.

Added a 'Delete' button to the new multiple file selection GUI window.

This simply deletes the last item in the list. This will be useful if the user clicks on the 'Add'
button too many times - instead of clicking 'Delete all' and having to re-select all files, now the
last element can be removed.