relax SVN archive

Created the 'scons binary_dist' target for Mac OS X.

Typing 'scons binary_dist' on a Mac will now create a DMG image of a universal Mac OS X application.

Added the Mac OS X DMG distribution file names to the scons script.

Modified the setup.py file so that the Mac OS X .app creation code is in the mac_setup() function.

This will be used by the scons system later on.

Updated the hdiutil command options for the Mac OS X DMG file creation.

Added instructions to the setup.py file for creating a Mac OS X DMG distribution file.

Removed the GUI wait_for_interpreter() method as this is replaced by the intepreter flush() method.

Mac OS X fix for the relaxation data list element - the height algorithm is now more robust.

The ListCtrl.GetSize() method appears not to work on Mac OS X!?! Therefore a different algorithm
has been designed to get around this Mac specific problem.

Fix for the relax_fit.relax_time GUI user function.

The combobox GetValue() call has been replaced by GetStringSelection() for the spectrum ID.

Removed the wx.Yield() call from the spin viewer window refresh() method.

This is to prevent recursive wx.Yield calls on Mac OS X from killing relax. This change might cause
instability though!

Fix for the Rx peak list wizard for Mac OS X.

The combobox SetValue() call has been replaced with SetStringSelection().