relax SVN archive

Fix for bug #17361 (https://gna.org/bugs/index.php?17361).

The chi2_sim structure should have been initialised to a list, not a dictionary.

Added a system test for reading relax 1.2.x version results files.

This is from Sebastian Morin's PSE-4 data, truncated, and is to catch the bug of not being able to
handle simulations.

Error messages are displayed for all the 'Execute relax' buttons when the execution lock is set.

Fix for the error message window - the caption argument default value should be '', not None!

The user function menu entires are disabled during relax execution lock.

This will prevent racing and strange crashing of relax.

Removed the 2 from CH2 in the atom list in the element determining function.

This is in response to Vitaly Vostrikov's <vvostri att gmail dott com> message at Message-id:
<AANLkTimYA4H7=WbMwzgpxaTJ6_nArKu=ed9VNdXCSuDB@...>,
https://mail.gna.org/public/relax-users/2010-12/msg00013.html.

The script user function is now executed in a thread from the GUI so that the GUI remains responsive.

All the user function dialogs are now modal.

The molecule user function dialogs are now modal.

Added support for CCPN Analysis 2.1 peak lists (exported in Sparky format).

This is a fix for bug #17341 (https://gna.org/bugs/index.php?17341) reported by Madeleine Strickland
<M dott Strickland att bristol dot ac dot uk>.