relax SVN archive

Fix for structure.read_pdb for when the file contains no PDB data.

This is now caught, and a warning is given and the function exists cleanly.

Created a basic system test checking the reading of a non-PDB file by structure.read_pdb.

Removed combine_models from the structure.load_spins user function page as that arg no longer exists.

Improvements to the free file format GUI elements (window and element).

This includes specifying fonts, button sizes, and a fix for the button sizer in the GUI element.

Fix for the model-free auto-analysis tab delete() method - the tab has no peak intensity object!

This was a copy of the NOE delete() method, but the list is for relaxation data rather than peak
intensities.

The GUI is now frozen while opening a relax state, and then finally thawed.

This removes visual artifacts on Mac OS X.

Removed the 'Settings->Reset all settings' menu and added a reset button to the free file format settings.

The only settings being reset were the free file format ones, so this has moved into that GUI element.

The Question class can now have the parent specified to allow for sub-windows to have the dialog focus.

The edit-delete oxygen icons are now more complete.

Fix for the wizard apply icon.